| Value |
Category |
| 00 |
Preschool |
| 01 |
Elementary school, grade 1 |
| 02 |
Elementary school, grade 2 |
| 03 |
Elementary school, grade 3 |
| 04 |
Elementary school, grade 4 |
| 05 |
Elementary school, grade 5 |
| 06 |
Elementary school, grade 6 |
| 11 |
General middle school, 1st year or grade 6 |
| 12 |
General middle school, 2nd year level I |
| 13 |
General middle school, 3rd year level I |
| 14 |
General middle school, 4th year level I |
| 15 |
General middle school, 1st year level II |
| 16 |
General middle school, 2nd year level II |
| 17 |
General middle school, 3rd year level II |
| 21 |
Technical education, 1st year level I |
| 22 |
Technical education, 2nd year level I |
| 23 |
Technical education, 3rd year level I |
| 25 |
Technical education, 1st year level II |
| 26 |
Technical education, 2nd year level II |
| 27 |
Technical education, 3rd year level II |
| 31 |
Higher education, 1st year at university |
| 32 |
Higher education, 2nd year at university |
| 33 |
Higher education, 3rd year at university |
| 34 |
Higher education, 4th year at university |
| 35 |
Higher education, 5th year at university |
| 36 |
Higher education, 6th year at university |
| 37 |
Higher education, 7th year at university |
| 98 |
Unknown |
| 99 |
NIU (not in universe) |
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.