| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 180 |
25.8%
|
| 1 | Has certificate | 232 |
33.2%
|
| 2 | Registered | 272 |
39%
|
| 8 | Don't know | 14 |
2%
|
| 9 | 25 | ||
| Sysmiss | 35707 |