| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 1235 |
32.4%
|
| 1 | Has certificate | 876 |
23%
|
| 2 | Registered | 1614 |
42.4%
|
| 8 | Don't know | 82 |
2.2%
|
| 9 | 142 | ||
| Sysmiss | 32481 |