| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 4 |
0.5%
|
| -9 | Don't know (spontaneous) | 8 |
1%
|
| 1 | Yes | 300 |
38.4%
|
| 2 | No | 469 |
60.1%
|
| Sysmiss | 315 |