| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 6600 |
31%
|
| 1 | Has certificate | 5135 |
24.2%
|
| 2 | Registered | 9053 |
42.6%
|
| 8 | Don't know | 471 |
2.2%
|
| 9 | 711 | ||
| Sysmiss | 131870 |