| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 58 |
30.1%
|
| 1 | Has certificate | 54 |
28%
|
| 2 | Registered | 78 |
40.4%
|
| 8 | DK | 3 |
1.6%
|
| 9 | 3 | ||
| Sysmiss | 8861 |