| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 358 |
31.2%
|
| 1 | Has certificate | 340 |
29.6%
|
| 2 | Registered | 429 |
37.3%
|
| 8 | DK | 22 |
1.9%
|
| 9 | 22 | ||
| Sysmiss | 7886 |