| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 25 |
5.3%
|
| 1 | has certificate | 0 |
0%
|
| 2 | registered | 433 |
92.5%
|
| 6 | other | 4 |
0.9%
|
| 8 | don't know | 6 |
1.3%
|
| Sysmiss | 44146 |