| Value | Category | Cases | |
|---|---|---|---|
| -99 | 11 |
3.6%
|
|
| 1 | Every few days | 2 |
0.6%
|
| 2 | Every few weeks | 15 |
4.9%
|
| 3 | Every few months | 103 |
33.3%
|
| 4 | Not at all | 141 |
45.6%
|
| Sysmiss | 37 |
12%
|