| Valeur | Catégorie | le cas | |
|---|---|---|---|
| 0 | neither certificate or registered | 4 |
22.2%
|
| 1 | has certificate | 11 |
61.1%
|
| 2 | registered | 2 |
11.1%
|
| 8 | don't know | 1 |
5.6%
|
| Sysmiss | 13233 |