| Value | Category |
|---|---|
| 03 | Upper secondary level education |
| 05 | Lowest level tertiary education |
| 06 | Lower-degree level tertiary education |
| 07 | Higher-degree level tertiary education |
| 08 | Doctorate or equivalent level tertiary education |
| 98 | Only primary education or level of education unknown |
| 99 | NIU (not in universe) |