| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 |
0.1%
|
| -7 | 7 |
0.7%
|
|
| 1 | Yes | 201 |
20.2%
|
| 2 | No | 786 |
79%
|
| Sysmiss | 415 |