| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 24 |
0.7%
|
| 1 | has certificate | 0 |
0%
|
| 2 | registered | 3249 |
97.6%
|
| 6 | other | 28 |
0.8%
|
| 8 | don't know | 29 |
0.9%
|
| Sysmiss | 41284 |