| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -9 | Don't know (spontaneous) | 1 |
0.2%
|
| 1 | Yes | 41 |
7.9%
|
| 2 | No | 479 |
91.9%
|
| Sysmiss | 251 |