| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 |
0.7%
|
| -7 | Does not apply (spontaneous) | 37 |
6.5%
|
| 1 | Yes | 75 |
13.1%
|
| 2 | No | 456 |
79.7%
|
| Sysmiss | 628 |