| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 21 |
14.1%
|
| 0 | 110 |
73.8%
|
|
| 10 | 6 |
4%
|
|
| 15 | 4 |
2.7%
|
|
| 20 | 2 |
1.3%
|
|
| 30 | 2 |
1.3%
|
|
| 50 | 4 |
2.7%
|