| Value | Category | 
|---|---|
| -99 | Don't know | 
| -98 | Refused to answer | 
| -77 | Other (please specify) | 
| 0 | Not enrolled in any school | 
| 1 | Pre-school | 
| 2 | Primary school | 
| 3 | Secondary school | 
| 4 | Tertiary education | 
| 2147483622 | Don't know | 
| 2147483623 | Refused to answer | 
| 2147483647 | Not applicable | 
| 11 | .Z |