| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -9 | Don't know (spontaneous) | 5 |
7.5%
|
| 0 | 54 |
80.6%
|
|
| 10 | 2 |
3%
|
|
| 20 | 2 |
3%
|
|
| 50 | 1 |
1.5%
|
|
| 60 | 2 |
3%
|
|
| 80 | 1 |
1.5%
|
|
| Sysmiss | 84 |