| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
1%
|
| 0 | 305 |
98.1%
|
|
| 20 | 1 |
0.3%
|
|
| 30 | 1 |
0.3%
|
|
| 39 | 1 |
0.3%
|