| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
1.1%
|
| -7 | Does not apply (spontaneous) | 4 |
0.7%
|
| 1 | Yes | 99 |
16.2%
|
| 2 | No | 502 |
82%
|