| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. never | 2903 |
85.7%
|
| 2 | 2. once or twice in a year | 313 |
9.2%
|
| 3 | 3. once or twice in a term | 100 |
3%
|
| 4 | 4. once or twice in a month | 30 |
0.9%
|
| 5 | 5. every week | 37 |
1.1%
|
| 11 | 6 |
0.2%
|
|
| Sysmiss | 1149 |