| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Yes | 18 |
9.5%
|
| 2 | No | 172 |
90.5%
|
| Sysmiss | 615 |