| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 9 |
1.7%
|
| -8 | Refusal (spontaneous) | 0 |
0%
|
| 0 | 26 |
5%
|
|
| 4 | 1 |
0.2%
|
|
| 5 | 18 |
3.5%
|
|
| 8 | 4 |
0.8%
|
|
| 10 | 420 |
80.9%
|
|
| 15 | 37 |
7.1%
|
|
| 20 | 4 |
0.8%
|