Population changes in the municipalities1951-2010


About the statistics


Name and topic

Name: Population changes in the municipalities
Topic: Population

Responsible division

Division for Population Statistics

Definitions of the main concepts and variables

Population: All figures cover the resident (de jure) population. The population of a municipality on 1 January is equal to the number of persons registered as residing in the municipality when all changes (births, deaths and migration) which took place up to 31 December of the previous calendar year are taken into consideration.

In the cases where a municipality's boundaries are changed effective 1 January, "population 1.1." describes the situation immediately after the boundary change was made. If no boundary change was made, "population 1.1." is equal to the population at 31 December of the previous calendar year.

Who is regarded as a resident of Norway and where in Norway a person shall be counted as a resident, is stipulated in the Population Registries Act of 15 November 1946, replaced by the Population Registration Act of 16 January 1970, which took effect 1 February 1970. The regulations to the act have been amended several times.

Amendments of laws and regulations in 1951-2007 have had only a minor effect on the number of residents or population in Norway.

For some municipalities, the changes in the rules for where a person shall be counted as a resident have had major consequences on the population. The main change was the rule that took effect on 1 February 1970 by which persons living in institutions (except for hospitals and prisons) or private homes, were usually counted as residents of the municipality in which the institution was located. The new registration rules had the greatest impact on Klæbu municipality, where the population immediately increased by around 20 per cent as a direct result of the rule change.

According to the regulations of 1 February 1970, single school pupils and students who live in another municipality than their municipality of residence are counted as residents of the school municipality, if they provided for themselves or were paid for on the job training. From 1 February 1980 the provider concept was eliminated as a criterion for being registered in the school municipality, without causing numerical changes of any extent.

The following main points from the registration rules show who was regarded as a resident of Norway in 1951-2007:

  • Persons from countries outside the Nordic countries are regarded as residents of Norway when they have lived here or intend to live here at least 6 months, even though the stay is temporary. The same six-month rule applies to migration from Norway to a country outside the Nordic countries.
  • With respect to migration between Norway and another Nordic country, the place of residence is decided pursuant to the rules of the county of immigration, cf. the Nordic agreement of 5 December 1968.
  • People living in Svalbard, on Jan Mayen or in Norwegian dependencies who on departure were registered as a resident of a Norwegian municipality shall still be counted as residents of that municipality. The same rules apply to people on the Norwegian continental shelf.

Births: Only live births are counted, i.e. foetuses that show signs of life at birth.

Excess of births over deaths: The excess of births over deaths, also called net natural increase in population, is equal to live births minus deaths.

In-migration, out-migration: Migration is the relocation of one person between two Norwegian municipalities or between a Norwegian municipality and abroad. People who move several times during a single calendar year are counted each time they move.

In the county tables, in-migration covers migration from other counties and from abroad. The same applies to out-migration. Note that the county figures for in-migration and out-migration for all years - except for 1951-1956 - are lower than the sum of the municipal figures for in- and out-migration respectively, since migration between municipalities within the county is not in the first mentioned figures.

In the national summary, in-migration and out-migration are equal to the migration totals from and to abroad respectively, see main points from the registration rules cited above.

Net migration: The difference between in-migration and out-migration. Migration between Norway and abroad is thus counted in all net migration figures.

Population growth: Population growth is equal to the increase (positive or negative) of the population over the course of a calendar year. On the precondition of unchanged boundaries, population growth is the difference between the population at 1 January that year and the population at 1 January the year before.

In principle, population growth is equal to the excess of births over deaths plus net in-migration. At the turn of the year the population was traditionally calculated as the population one year before to which is added the excess of births over deaths and net in-migration in the 12-month period. For 1955, 1960, 1966 and 1968 and later years the "account" usually does not agree in practice, see section 6.1.

Final - preliminary figures: All population figures in this publication are final figures.

Municipality: Before 1965 a municipality was usually identical with a town or a rural district, cf. earlier name of the annual publication. A town was either a market town or small seaport. On the other hand, some ports were not separate municipalities. After 1950 this only applied to 0202 Hvitsten and 0603 Holmsbu, which belonged to the municipalities 0211 Vestby and 0628 Hurum respectively. The statistics do not give separate figures for Hvitsten and Holmsbu.

From 1 January 1965 municipalities went by the designation urban municipality or rural municipality. The Local Government Act from 1992 makes no distinction between urban and rural municipalities.

Municipality number: In 1946 all municipalities - and small seaports that were not separate municipalities - were assigned a 4-digit code (called "number") by Statistics Norway. The first two digits indicate the county. Urban municipalities (and towns before 1965) got a municipality number in which the third digit is a zero.

Standard classifications


Administrative information

Regional level


Frequency and timeliness


International reporting

Not relevant.


Main files individual level will be stored, as well as some intermediate files.


Background and purpose

Together with other subject areas in population statistics, the statistics shall help show the changes taking place that influence the composition and geographic distribution of the population.

Statistics Norway has been publishing annual statistics on population, births, deaths and migration in each municipality since 1951. Annual figures for each municipality for the 30-year period 1951-1980 was assembled in the three volumes of the publication NOS Population in Municipalities (Folketallet i kommunene) 1951-1980: Volume I Østlandet, Volume II Sørlandet and Vestlandet and Volume III Trøndelag and Nord-Norge. Each of the volumes contains national overviews of changes in municipal divisions in 1951-1980, the population of transferred areas etc. An extended overview comprising changes in municipal divisions in 1838-1998, was later published in Historisk oversikt over endringer i kommune- og fylkesinndelingen (Rapporter 99/13) (Historical Overview of Changes in Municipal and County Divisions (Reports 99/13)).

The purpose of publishing the information on Statistics Norway's website is to make time series for the entire period more easily accessible to users. The time series will be updated.

Due to the many and extensive changes in municipal boundaries during the period - particularly in the 1960s - time series are often not comparable. No attempt has been made in this on-line publication to make the numbers more comparable. On the other hand, the publication NOS Population in Municipalities 1951-1980 (Folketallet i kommunene) gives population figures dating back to 1951 computed by the Norwegian Social Science Data Services (NSD) for municipal units that existed in 1980. Table 1 in the municipal volumes published in conjunction with the 2001 Population and Housing Census also contains as comparable as possible population figures for municipal units during most population censuses dating back to 1875. Where exact time series could not be obtained, NSD estimates, with exceptions for minor boundary changes, are given. Changes in municipal divisions in 1875-2007 are given in section 6.

Users and applications

The statistics have a wide spectrum of users and applications, such as institutes engaged in demographics research, public administration, the mass media and private persons.

Coherence with other statistics

With few exceptions the figures in the tables correspond with the figures in the annual publications NOS Folkemengden i herreder og byer (Population in Rural Districts and Towns), NOS Folketallet i kommunene (Population in Municipalities) and NOS Befolkningsstatistikk (Population Statistics).

The discrepancies are because

i) small errors occur in the annual publications (printing errors, transposition errors and the like)

ii) certain figures in the annual publications do not correspond with the boundary changes (usually incorrect migration figures)

iii) "final" figures for the population on 1 January 1967 in the publication NOS Folketallet i kommunene 1966-1968 (Population of the Municipalities 1966-1968) were revised in the next edition.

The corrections mentioned under subsection i) and ii) are not marked in the tables. The corrections only concern municipality numbers and have not affected county and national figures in this publication.

In some publications, e.g. NOS Folkemengden etter alder og ekteskapelig status (Population by Age and Marital Status), figures are given for population at 31 December. Should a municipality's boundaries be changed effective 1 January, the population at 31 December for one calendar year will not be the same as the population on 1 January of the following calendar year (the day after). On a national basis the population on 31 December and 1 January (the day after) are identical, as in both cases the changes that apply 31 December are taken into consideration, but the persons are distributed differently on the municipalities.

The publication NOS Folkemengden etter alder 31. desember 1965 (Population by Age 31 December 1965), being the very first one based on the Central Population Register, gives somewhat different population figures. Furthermore, time series in NOS Folkemengden etter alder og ekteskapelig status 31. desember (Population by Age and Marital Status 31 December), editions 1978-1984, and succeeding editions of NOS Befolkningsstatistikk (Population Statistics) give other, newer estimates for national figures for most years before 1970. These figures are taken from NOS Historiske tabeller over folkemengde, giftermål og dødsfall 1911-1976 (Historical Tables on Population, Marriages and Deaths 1911-1976), described in Utviklingen i giftermål og dødsfall 1911-1976 (The Development in Marriages and Deaths 1911-1976), Statistical Analyses no. 35.

The migration numbers for municipalities in 1951-1953 and 1955-1957 do not give the national totals given in NOS Flyttestatistikk 1974 (Migration Statistics 1974) and later editions and in older editions of NOS Folkemengdens bevegelse (Vital Statistics and Migration Statistics). The discrepancies are due to somewhat different basic data. For in-migration and out-migration, however, the National Summary nevertheless includes figures from NOS Flyttestatistikk (Migration Statistics)/NOS Befolkningsstatistikk (Population Statistics), as other data are missing.

Computing "new" figures In cases where municipalities have been split, the population of the new units (at the time of the division) has not been listed in the annual publications. In the cases where the population account for the first calendar year after the division has agreed, the population at the time of the division was calculated by counting backwards on the basis of population one year later and the change figures (births, deaths, migration) for the first calendar year. In case of a discrepancy in the "account" the discrepancy is divided proportionally with the population.

In cases of municipal mergers the annual publication has not always shown the population growth in the relevant municipalities in the last year. To the extent a statistical basis has nevertheless existed, (e.g. the population in Bergen on 31 December 1971), figures are given. Where the population account does not agree, the discrepancy is divided proportionally with the population.

Legal authority

Statistics Act §§ 2-1, 2-2, 3-2.

EEA reference

Not relevant.



The statistics cover persons and events (births, deaths and migration) that apply to persons registered as residing (domiciled) in Norway at the time of the census/event, regardless whether the event took place in Norway or abroad. Live births cover only births where the child's mother was registered as residing in Norway at the time of the birth. In the same way, residents and events are assigned to the individual municipality. Migration covers all registered migration between Norwegian municipalities and between a Norwegian municipality and abroad. People who move several times during a single calendar year are counted each time they move.

Delayed reporting in population registration has been handled in different ways in the statistics without having any appreciable effect on the time series.

Data sources and sampling

The statistics are based on population register data.

As a result of the Population Registers Act of 15 November 1946 (replaced by the Population Registration Act of 16 January 1970) each municipality established a population registry where all residents of the municipality were to be registered. The 3 December 1946 and 1 December 1950 censuses were important starting points for the population registers.

People who moved had to notify the population registry. Together with annual numbers of births and deaths these notifications of change of address have made it possible to calculate the population of each municipality one year at a time since 1951. A manual count in the population registers as of 1 January 1956 and censuses conducted on 1 November 1960 and 1970 were used to correct the population registers.

From 1 January 1968 to 1995, the population was based on counts in the National Population Register and later on Statistics Norway's population base.

The source for the statistics on live births has always been birth reports from hospitals, maternity clinics or midwives, sent via the local population registry. For deaths the sources has been death reports from probate courts/sheriffs via the population registry, which until 1985 were compared with reports of deaths from public doctors. Reports of deaths abroad of residents of Norway are obtained in part from the Ministry of Foreign Affairs and in part from the Directorate for Seamen. Since 1985 all information on births and deaths has been received by Statistics Norway via the National/Central Population Register.

Notifications of change of address come from the population registries. Whoever moves is required by the regulations of the Population Registration Act to report to the population registry of the municipality to which he/she has moved. Overseas moves are reported to the municipality in which the person lives.

The National Population Register (DSP) was built up from 1964 to 1966 on the basis of the 1960 census, at the same time as the 11-digit national identity number was introduced as identification. In 1995, the Central Population Register at the Directorate of Taxes took over as the official register. The Office of the National Registrar, which administrates the DSF (and previous DSP), was transferred in 1991 from Statistics Norway to the Directorate of Taxes.

Updating of the Central Population Register is done in part by the local population registries, which are connected to the DSF via terminals, and in part centrally by the Directorate of Taxes. The basis of the statistics on changes in the population is electronic copies to Statistics Norway of all such reports of events that update the register. Since 1985, the reports are also used to update a separate Statistics Norway population database kept for statistical purposes. This base, which inter alia functions as a copy of the DSF, forms the basis for all current register-based population statistics, including demographic changes in the population.

Not relevant.

Collection of data, editing and estimations

Not relevant.

In addition to the checks that are regularly performed by the population registries and the National/Central Population Register, Statistics Norway carries out checks for statistical purposes. More details about the checks that are now undertaken are given in Dokumentasjon av BESYS-befolkningsstatistikksystemet. Befolkningsendringer i 1998 og befolkningsbasen (BEBAS) 1. januar 2000, Notater 2000/24 (in Norwegian only)

The statistical material is based on the material used in the printed publication Population in Municipalities 1951-1980 Vol. I-III (Folketallet i kommunene 1951-1980 Hefte I-III), published in 1982. The statistical basis of the latter publication was the result of close cooperation with Norwegian Social Science Data Services (NSD) in Bergen.

Data for 1951-1967 were obtained from the annual publications NOS Folkemengden i herreder og byer (Population in Rural Districts and Towns) and NOS Folketallet i kommunene (Population in Municipalities). Figures for men and women were totalled, the excess of births over death and population growth computed, and controls (particularly of totals) were done. The statistical material was then recorded on computer and sent to NSD on magnetic tape.

At NSD the data for 1951-1967 were supplemented with data for 1968-1980, partly with the help of data already in NSD's hands and partly with the help of data NSD received in conjunction with the venture.

During the editing of the magnetic tape, which was to serve as the basis for tables, the data were carefully checked, inter alia against NSD's Municipal Databank. National and county totals were run out, checked and made to correspond with previously published figures. The tables were produced by Statistics Norway.

Boundary changes and times were checked against the Municipal Databank. In some cases the local population registries were contacted.

Statistics Norway has supplemented the statistical material for 1951-1980 with statistics for 1981-2007. The figures for in-migration and out-migration in 1951-1957 in the printed publication, which only covered domestic migration, were replaced by total migration figures, in that figures for migration to and from Norway in 1951-1957 were obtained from the municipal volumes of the 1960 Population Census.


Not relevant.

Comparability over time and space

Editing of the tables: No attempt was made to prepare comparable time series for municipalities affected by the many changes in municipal boundaries in 1951-2007. The number of municipalities in Norway varied between 744 and 431

Changes in municipal boundaries and population consequences of the changes are described in detail in footnotes to the tables. In order to give users the best possible basis for "repairing" breaks in the time series the printed publication NOS Population in Municipalities 1951-1980 Volume I-III contained several annexes describing boundary changes and population figures in the areas involved. An extended overview of main items of these annexes is published in NOS Historisk oversikt over endringer i kommune- og fylkesinndelingen (Historical overview of municipal and county changes) (Rapporter 99/13) by Dag Juvkam. This publication covers the period 1838-1998.

In total there are 744 municipal tables, one for each municipal unit that existed in 1951. In many cases, figures for units that have not been identical in the period 1951-1999 have been gathered in one table. The cases may be grouped as such:

1. Municipalities that have received or lost a small amount of land in connection with a boundary change.

Example: 0301 Oslo and 1925 Sørreisa.

2. Municipalities that have been merged with one or more municipalities where the new unit has been given the number (and usually also the name) of the new (usually the largest) municipality.


a. 0101 Halden both before and after the merger 1 January 1967.

b. 0119 Nymark before and 0119 Marker after the merger 1 January 1964.

3. Municipalities that have been merged with one or more municipalities and which after a time have gone back to being a separate municipality (regardless of whether municipality numbers and/or area is identical before the merger).

Example: 0435 Os (1951-1965), 0435 Tolga-Os (1966-1975) and 0441 Os (1976-2007).

1. Municipal units with the same municipality number are with few exceptions placed in the same table. The following three exceptions are cases where the same municipality number is used for two completely separate geographic areas:

0516 Heidal (1951-1964) and 0516 Nord-Fron (1977-2007)

1523 Sunnylven (1951-1964) and 1523 Ørskog (1977-2007)

1923 Øverbygd (1951-1963) and 1923 Salangen (1977-2007)

Order and numbering of the tables: The tables have no sequential numbering. They are placed according to municipality number in the top left-hand corner, i.e. the municipality number that is given first in the table heading. In case more than one municipality number (or name) is given, the most relevant (chronological) is first. (Example: The table with the heading "0441 Os, 0435 Tolga-Os, 0435 Os" is placed after 0440 Kvikne.)

Separate searches on the web can be made of existing municipalities in 2007 (green mark) and no longer existing municipalities (red).

Change of municipality number: As to mergers up to 1976 the municipality number of one of the municipalities involved was used again. However, this principle could not be continued for demergers in 1976 and 1977, because the authorities had started to use the municipality number as a part of the account number for paying in taxes to the chief cashier. Even if the principle followed up to 1976 could have been used at mergers later, it was decided to assign new numbers for merged municipalities. An exception, however, applies to Vestfold county where previously used numbers for "urban municipalities" were assigned again, because of too few never used such numbers.

In 1976-1977 five municipalities received previously unused municipality numbers (0441 Os, 0605 Ringerike, 1449 Stryn, 1504 Ålesund and 1874 Moskenes), while the five other municipalities (0516 Nord-Fron, 1231 Ullensvang, 1523 Ørskog, 1813 Brønnøy and 1923 Salangen) received numbers that had not been used for nine to 13 years. The remaining 11 "new" municipalities resulting from divisions (including 1531 Sula) got their municipality numbers back, although only seven of them had exactly the same boundaries.

Break in the population account: The reasons that the "population accounts" mentioned in section 4.1 (under population growth) usually do not agree for the years 1955, 1960, 1966, 1968 and later is because of the basis on which the population is calculated:

  • The basis for the population at 1 January 1956 was a counting in the population registers at this time (regardless of the numbers a projection from 1 January 1955 would have given).
  • The population at 1 January 1961 was projected on the basis of results from the census of 1 November 1960 (which was independent of the figures at 1 January 1960).
  • Starting 1 January 1968 the population is a result of annual counts of residents in the National/Central Population Register. The discrepancies for 1968 and later are due to the fact that the central register is continuously updated with all the changes that are reported, including those that concern previous years but did not get included in the year in question's edition of statistics on births, deaths and migration (change numbers). On the basis of the counted population on 1 January 1968, new (revised) figures for population at 1 January 1967 were computed with the help of change numbers for 1967. This is why the "population account" for 1967 agrees, while there is a discrepancy for 1966.

The discrepancies are the greatest for the years 1955, 1960, 1966 and 1970-1971. For the two latter years, the reason is that the National Population Register was corrected on the basis of the 1970 census. Not all correction work was finished when the population numbers at 1 January 1971 were prepared.

The tables show horizontal break lines wherever the time series are not comparable, with a note explaining why. The main reason for breaks is changed municipal boundaries.

Accuracy and reliability

Sources of error and uncertainty

Some errors made during the collecting and processing of the data are unavoidable and include coding, revision and data processing errors etc. Extensive efforts have been made to minimize these errors, and we regard these types of errors to be relatively insignificant.

Not relevant.

Not relevant.

The quality of the basic data from the National Population Register is generally very good for statistical purposes. However, delayed notifications and residence registration are two area of improvement. As a result of delayed notifications occurrences are not registered and counted in the correct calendar year. This is less problematic when statistics for several years are summarised. For information on the problems with residence registration, see http://www.ssb.no/english/subjects/02/01/10/folkemengde_en/