| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 |
15%
|
| 0 | 1 |
5%
|
|
| 1 | 1 |
5%
|
|
| 5 | 1 |
5%
|
|
| 10 | 3 |
15%
|
|
| 15 | 2 |
10%
|
|
| 20 | 1 |
5%
|
|
| 25 | 1 |
5%
|
|
| 30 | 6 |
30%
|
|
| 50 | 1 |
5%
|
|
| Sysmiss | 239 |