Yearly decrease

In general terms, this means the change in the index value in a calendar year relative to the value in the preceding year. Annual change is calculated by comparing the average of the monthly indices for the whole year with the corresponding averages for the previous year. Annual changes should not be confused with twelve-month rates of change, which specify the development of an index value from one month in a particular year with the same month in the following year. Both the annual change and the twelve-month change is calculated from calendar adjusted figures.