| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 |
11.9%
|
| 0 | None | 31 |
73.8%
|
| 1 | 5 |
11.9%
|
|
| 5 | 1 |
2.4%
|
|
| Sysmiss | 217 |