| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 7 |
18.4%
|
| 0 | None | 25 |
65.8%
|
| 2 | 3 |
7.9%
|
|
| 5 | 3 |
7.9%
|
|
| Sysmiss | 337 |