| Value | Category |
|---|---|
| 1 | finished 9 classes (8 classes) |
| 2 | finished secondary school, gymnasium, lyceum |
| 3 | technical school, college, secondary-professional |
| 4 | bachelor’ degree |
| 5 | higher education or master’s degree |
| 6 | doctor’s degree |
| 7 | has none of the above listed |
| 22 | |
| Sysmiss |