| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 12 |
0.9%
|
| -7 | Does not apply (spontaneous) | 34 |
2.5%
|
| 1 | Yes | 431 |
32.3%
|
| 2 | No | 858 |
64.3%
|
| Sysmiss | 2 |