| 1996 | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 | Number of respondents | 
 2 561 | 
   | 
   | 
  335 | 
  257 | 
   | 
  296 | 
  298 | 
  358 | 
  387 | 
  314 | 
  316 | 
 |   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 | Total | 
  100.0 | 
   | 
   | 
  100.0 | 
  100.0 | 
   | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
 | Unknown | 
 2.1 | 
   | 
   | 
 - | 
 1.6 | 
   | 
 1.7 | 
 1.7 | 
 2.5 | 
 2.6 | 
 1.9 | 
 6.3 | 
 | Not completed primary school | 
 22.0 | 
   | 
   | 
 6.9 | 
 45.5 | 
   | 
 7.0 | 
 15.4 | 
 43.9 | 
 18.6 | 
 12.4 | 
 14.6 | 
 | Primary school | 
 14.9 | 
   | 
   | 
 18.2 | 
 17.5 | 
   | 
 3.0 | 
 26.8 | 
 10.9 | 
 10.6 | 
 16.9 | 
 3.5 | 
 | Upper secondary education | 
 41.5 | 
   | 
   | 
 47.5 | 
 23.7 | 
   | 
 44.9 | 
 44.3 | 
 33.5 | 
 48.8 | 
 50.6 | 
 45.9 | 
 | Tertiary education | 
 19.5 | 
   | 
   | 
 27.5 | 
 11.7 | 
   | 
 42.9 | 
 11.7 | 
 9.2 | 
 19.4 | 
 18.2 | 
 29.7 | 
 |   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 | 2005/2006 | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 | Number of respondents | 
 3 048 | 
  333 | 
  288 | 
   | 
  297 | 
  357 | 
  269 | 
  306 | 
  313 | 
  353 | 
  244 | 
  288 | 
 |   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 | Total | 
  100.0 | 
  100.0 | 
  100.0 | 
   | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
  100.0 | 
 | Not completed any education | 
 13.2 | 
 10.2 | 
 9.7 | 
   | 
 10.4 | 
 15.4 | 
 8.2 | 
 10.8 | 
 23.6 | 
 3.4 | 
 27.9 | 
 8.0 | 
 | Primary school or less | 
 18.9 | 
 7.5 | 
 16.7 | 
   | 
 40.4 | 
 20.2 | 
 8.2 | 
 27.1 | 
 16.9 | 
 15.3 | 
 17.6 | 
 10.1 | 
 | Upper secondary education | 
 40.8 | 
 50.7 | 
 53.4 | 
   | 
 30.9 | 
 30.0 | 
 38.6 | 
 37.3 | 
 38.7 | 
 56.6 | 
 36.9 | 
 46.2 | 
 | Tertiary education | 
 25.7 | 
 30.3 | 
 20.2 | 
   | 
 17.1 | 
 32.7 | 
 43.5 | 
 23.2 | 
 18.1 | 
 23.2 | 
 16.7 | 
 33.6 | 
 | Not specified | 
 1.6 | 
 1.2 | 
 - | 
   | 
 1.0 | 
 1.7 | 
 1.5 | 
 1.6 | 
 2.6 | 
 1.4 | 
 0.8 | 
 2.1 | 
  |