| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
0.5%
|
| 1 | Yes | 24 |
3.8%
|
| 2 | No | 597 |
95.5%
|
| 3 | 1 |
0.2%
|
|
| Sysmiss | 807 |