| Value | Category |
|---|---|
| 1 | none or some primary |
| 2 | completed primary 4 years |
| 3 | completed primary 7/8 years |
| 4 | some secondary general |
| 5 | completed secondary |
| 6 | some vocational school |
| 7 | completed vocational school |
| 8 | some university |
| 9 | completed university degree |
| 97 | don't know |
| Sysmiss |