| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 184 |
44.6%
|
| 1 | Has certificate | 86 |
20.8%
|
| 2 | Registered | 128 |
31%
|
| 8 | DK | 15 |
3.6%
|
| 9 | 10 | ||
| Sysmiss | 8634 |