| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 1073 |
13.3%
|
| 1 | has certificate | 1346 |
16.7%
|
| 2 | registered | 5620 |
69.6%
|
| 8 | don't know | 30 |
0.4%
|
| Sysmiss | 47851 |