| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 128 |
11.2%
|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Yes | 124 |
10.8%
|
| 2 | No | 893 |
78%
|
| Sysmiss | 178 |