| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
5.1%
|
| 0 | None | 34 |
57.6%
|
| 1 | 4 |
6.8%
|
|
| 2 | 2 |
3.4%
|
|
| 3 | 4 |
6.8%
|
|
| 7 | 1 |
1.7%
|
|
| 10 | 5 |
8.5%
|
|
| 15 | 5 |
8.5%
|
|
| 20 | 1 |
1.7%
|
|
| Sysmiss | 309 |