| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| -7 | Does not apply (spontaneous) | 6 |
1.7%
|
| 1 | Yes | 23 |
6.4%
|
| 2 | No | 331 |
91.9%
|