| Value | Category |
|---|---|
| -9 | REFUSED |
| -7 | DON'T KNOW |
| 1 | NO FORMAL SCHOOLING |
| 2 | PRIMARY |
| 3 | SECONDARY |
| 4 | TECHNICAL OR TRADE SECONDARY |
| 5 | NORMAL BASIC |
| 6 | PREPARATORY OR VOCATIONAL |
| 7 | TECHNICAL HIGH SCHOOL |
| 8 | TECHNICAL OR TRADE DEGREE |
| 9 | NORMAL UPPER-LEVEL |
| 10 | UNDERGRADUATE |
| 11 | MASTERS / DOCTORATE |