| Value | Category |
|---|---|
| 1 | no formal education |
| 2 | less than primary(incomplete) school |
| 3 | complete primary school |
| 4 | incomplete secondary school (junior one) |
| 5 | completed secondary school (junior two) |
| 6 | higher education than secondary school |
| 7 | adult education only |
| 8 | college/university or more |
| 88 | don't know |
| 99 | |
| Sysmiss |