| Value | Category | Cases | |
|---|---|---|---|
| -9 | do not know | 2 |
1.4%
|
| 0 | 140 |
94.6%
|
|
| 10 | 4 |
2.7%
|
|
| 20 | 1 |
0.7%
|
|
| 30 | 1 |
0.7%
|