| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
0.5%
|
| -7 | Does not apply (spontaneous) | 45 |
4.2%
|
| 1 | Yes | 165 |
15.6%
|
| 2 | No | 846 |
79.7%
|
| Sysmiss | 1008 |