| Value | Category | Cases | |
|---|---|---|---|
| 0 | no | 2765 |
89.6%
|
| 1 | yes | 312 |
10.1%
|
| 8 | don't know | 4 |
0.1%
|
| 9 | 4 |
0.1%
|
|
| 11 | .Z | 15669 |