| Valeur | Catégorie | le cas | |
|---|---|---|---|
| 0 | Neither certificate or registered | 27 |
5.4%
|
| 1 | Has certificate | 416 |
83.4%
|
| 2 | Registered | 52 |
10.4%
|
| 8 | Don't know | 4 |
0.8%
|
| 9 | 37 | ||
| Sysmiss | 3946 |