| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
25%
|
| 1 | 1 |
25%
|
|
| 5 | 1 |
25%
|
|
| 30 | 1 |
25%
|
|
| Sysmiss | 348 |