| Valeur | Catégorie | le cas | |
|---|---|---|---|
| 0 | Neither certificate or registered | 13 |
4.5%
|
| 1 | Has certificate | 238 |
82.4%
|
| 2 | Registered | 36 |
12.5%
|
| 8 | Don't know | 2 |
0.7%
|
| 9 | 29 | ||
| Sysmiss | 4164 |