| Value | Category | Cases | |
|---|---|---|---|
| -99 | 3 |
2.5%
|
|
| 1 | Every few days | 6 |
5%
|
| 2 | Every few weeks | 13 |
10.8%
|
| 3 | Every few months | 55 |
45.8%
|
| 4 | Not at all | 43 |
35.8%
|
| Sysmiss | 24 |