| Valeur | Catégorie | le cas | |
|---|---|---|---|
| 0 | Neither certificate or registered | 2 |
9.1%
|
| 1 | Has certificate | 16 |
72.7%
|
| 2 | Registered | 3 |
13.6%
|
| 8 | Don't know | 1 |
4.5%
|
| 9 | 1 | ||
| Sysmiss | 4459 |