| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 257 |
39.9%
|
| 1 | Has certificate | 138 |
21.4%
|
| 2 | Registered | 223 |
34.6%
|
| 8 | DK | 26 |
4%
|
| 9 | 12 | ||
| Sysmiss | 8401 |