| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -77 | Does not apply | 0 |
0%
|
| -9 | Don't know (spontaneous) | 25 |
3.1%
|
| -7 | Does not apply (spontaneous) | 104 |
12.9%
|
| 1 | Yes | 138 |
17.1%
|
| 2 | No | 539 |
66.9%
|
| Sysmiss | 640 |