| 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 |