| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -9 | Don't know (spontaneous) | 2 |
20%
|
| 0 | 3 |
30%
|
|
| 1 | 2 |
20%
|
|
| 2 | 1 |
10%
|
|
| 5 | 2 |
20%
|
|
| Sysmiss | 350 |