| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 30 |
5%
|
| 0 | 525 |
87.5%
|
|
| 5 | 8 |
1.3%
|
|
| 10 | 12 |
2%
|
|
| 15 | 1 |
0.2%
|
|
| 20 | 10 |
1.7%
|
|
| 25 | 4 |
0.7%
|
|
| 30 | 4 |
0.7%
|
|
| 40 | 4 |
0.7%
|
|
| 100 | 2 |
0.3%
|