| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 170 |
35%
|
| 1 | Has certificate | 101 |
20.8%
|
| 2 | Registered | 198 |
40.7%
|
| 8 | Don't know | 17 |
3.5%
|
| 9 | 15 | ||
| Sysmiss | 35929 |