| Value | Category | Cases | |
|---|---|---|---|
| 0 | Neither certificate or registered | 3 |
75%
|
| 1 | Has certificate | 1 |
25%
|
| 2 | Registered | 0 |
0%
|
| 8 | Don't know | 0 |
0%
|
| 9 | 2 | ||
| Sysmiss | 36424 |