| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 809 |
36.4%
|
| 1 | Has certificate | 416 |
18.7%
|
| 2 | Registered | 933 |
42%
|
| 8 | Don't know | 62 |
2.8%
|
| 9 | 70 | ||
| Sysmiss | 34140 |