| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.5%
|
| 0 | 450 |
94.9%
|
|
| 5 | 3 |
0.6%
|
|
| 10 | 4 |
0.8%
|
|
| 15 | 1 |
0.2%
|
|
| 20 | 4 |
0.8%
|
|
| 30 | 3 |
0.6%
|
|
| 35 | 1 |
0.2%
|
|
| 50 | 1 |
0.2%
|