| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 2223 |
36.6%
|
| 1 | Has certificate | 1571 |
25.9%
|
| 2 | Registered | 2132 |
35.1%
|
| 8 | DK | 151 |
2.5%
|
| 9 | 114 | ||
| Sysmiss | 32324 |