| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 13 |
19.7%
|
| 1 | has certificate | 9 |
13.6%
|
| 2 | registered | 44 |
66.7%
|
| 8 | don't know | 0 |
0%
|
| Sysmiss | 12883 |