| Value | Category |
|---|---|
| 0 | grade 0/r or grade 1 incomplete |
| 1 | grade 1 |
| 2 | grade 2 |
| 3 | grade 3 |
| 4 | grade 4 |
| 5 | grade 5 |
| 6 | grade 6 |
| 7 | grade 7 |
| 8 | grade 8 |
| 9 | grade 9 |
| 10 | grade 10 |
| 11 | grade 11 |
| 12 | grade 12 |
| 13 | diploma |
| 14 | degree |
| 15 | too young to attend school |
| 16 | never educated |
| 17 | informal education |
| 20 | special school |