| Value | Category |
|---|---|
| 1 | no formal education or less than isced 1 |
| 2 | primary education (isced 1) |
| 3 | lower secondary (isced 2) |
| 4 | upper secondary (isced 3) |
| 5 | post-secondary non-tertiary (isced 4) |
| 6 | tertiary education- bachelor or master (isced 5) |
| 7 | tertiary education-phd (isced 6) |
| 99 | don't know |
| Sysmiss |