PEDUC							     ISCED97	   LIS recode
  0 preceeding first level (ISCED-1976)						1
  1 first level									1
  2 second level, first stage							1
  3 second level, second stage							2
  5 third level, first stage , non-university					3
  6 third level, first stage , university degree				3
  7 third level, second stage , post university degree				3