| Value | Category |
|---|---|
| 1 | None |
| 2 | Pre-school |
| 4 | |
| 5 | |
| 6 | |
| 11 | P1 |
| 12 | P2 |
| 13 | P3 |
| 14 | P4 |
| 15 | P5 |
| 16 | P6 |
| 17 | JSS1 |
| 18 | JSS2 |
| 19 | JSS3 |
| 20 | M1 |
| 21 | M2 |
| 22 | M3 |
| 23 | M4 |
| 24 | SSS1 |
| 25 | SSS2 |
| 26 | SSS3 |
| 27 | SSS4 |
| 28 | 'O' level |
| 29 | 'A' level |
| 30 | Polytechnic |
| 31 | Training College |
| 32 | University |
| 33 | Medical Training institution |
| 2147483636 | Other (specify) |
| 101 | .S |
| Sysmiss |