| Value | Category |
|---|---|
| 1 | Primary(1-4 forms) |
| 2 | Lower 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 |