| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 40 |
15.9%
|
| 1 | has certificate | 50 |
19.8%
|
| 2 | registered | 162 |
64.3%
|
| 8 | don't know | 0 |
0%
|
| Sysmiss | 12697 |