PEDUC							     ISCED97	   LIS recode
  1  less than first stage of secondary level 					1
  2  first stage of secondary level						1
  3  second stage of secondary level						2
  4  third level other than university degree 					3
  5  initial university degree, or eqivalent 					3
  6  higher university degree, or post-doctorate				3
 -1  unknown									9