| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
0.3%
|
| -7 | Does not apply (spontaneous) | 25 |
4.4%
|
| 1 | Yes | 129 |
22.6%
|
| 2 | No | 416 |
72.7%
|
| Sysmiss | 628 |