| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 42 |
48.3%
|
| 1 | has certificate | 37 |
42.5%
|
| 2 | registered | 5 |
5.7%
|
| 8 | don't know | 3 |
3.4%
|
| 11 | .Z | 15580 |