| Value | Category | 
|---|---|
| 1 | Incomplete secondary school (8-9 years) or less | 
| 2 | Specialized secondary school (technical or vocational school | 
| 3 | Complete secondary school (10-11 years) | 
| 4 | Incomplete higher education or bachelor`s degree | 
| 5 | Complete higher education, master`s degree or greater | 
| 9 | DK/NR |