| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
4.6%
|
| 0 | 63 |
41.7%
|
|
| 20 | 1 |
0.7%
|
|
| 30 | 1 |
0.7%
|
|
| NA | 79 |
52.3%
|