| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 20 |
20%
|
| 0 | 74 |
74%
|
|
| 20 | 1 |
1%
|
|
| 30 | 1 |
1%
|
|
| 50 | 2 |
2%
|
|
| 70 | 1 |
1%
|
|
| 90 | 1 |
1%
|
|
| Sysmiss | 265 |