| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 |
4.3%
|
| 1 | 37 |
78.7%
|
|
| 2 | 5 |
10.6%
|
|
| 4 | 3 |
6.4%
|
|
| Sysmiss | 264 |