| Value | Category | Cases | |
|---|---|---|---|
| 0 | neither certificate or registered | 683 |
34.7%
|
| 1 | has certificate | 1046 |
53.2%
|
| 2 | registered | 215 |
10.9%
|
| 8 | don't know | 14 |
0.7%
|
| 9 | 10 |
0.5%
|
|
| 11 | .Z | 13699 |