| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 38 |
6.4%
|
| -8 | Refusal (spontaneous) | 35 |
5.9%
|
| 0 | 524 |
87.6%
|
|
| 10 | 1 |
0.2%
|