| Value | Category |
|---|---|
| 1 | Primary(1-4 forms) |
| 2 | ?ower secondaryl (5-9) |
| 3 | Upper secondary (10-12) |
| 4 | Preliminary vocational (handicraft, industrial) |
| 5 | Middle vocational ( technical college , college) |
| 6 | Higher (bachelor degree, master degree) |
| 7 | Post-graduate |
| Sysmiss |