| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 6 |
26.1%
|
| 1 | has certificate | 2 |
8.7%
|
| 2 | registered | 15 |
65.2%
|
| 8 | don't know | 0 |
0%
|
| Sysmiss | 12926 |