| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 |
0%
|
| 1 | Never | 1 |
0.2%
|
| 2 | Once a year or less frequent | 17 |
3.9%
|
| 3 | Two or three times a year | 23 |
5.2%
|
| 4 | Quarterly | 129 |
29.4%
|
| 5 | Monthly or more often | 269 |
61.3%
|
| Sysmiss | 162 |