| Value | Category |
|---|---|
| 1 | director and owner od enterprise (public and private sector) |
| 2 | proefessionals and artists (with university diploma) |
| 3 | qualified blue collars |
| 4 | white collars |
| 5 | service sector (trade, caterer, craftsman) |
| 6 | unqualified and semi-qualified blue collars |
| 999998 | refusal |
| 999999 | dontknow |
| Sysmiss |