| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 |
5.3%
|
| 0 | 105 |
92.1%
|
|
| 10 | 1 |
0.9%
|
|
| 20 | 1 |
0.9%
|
|
| 40 | 1 |
0.9%
|