| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 24 |
51.1%
|
| 1 | has certificate | 21 |
44.7%
|
| 2 | registered | 2 |
4.3%
|
| 8 | don't know | 0 |
0%
|
| 11 | .Z | 15620 |