| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
8.3%
|
| 5 | 3 |
25%
|
|
| 8 | 3 |
25%
|
|
| 15 | 3 |
25%
|
|
| 20 | 1 |
8.3%
|
|
| 30 | 1 |
8.3%
|
|
| Sysmiss | 333 |