| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.8%
|
| 0 | 248 |
63.9%
|
|
| 10 | 5 |
1.3%
|
|
| 20 | 8 |
2.1%
|
|
| 25 | 120 |
30.9%
|