| Value | Category | Cases | |
|---|---|---|---|
| 1 | Never | 1960 |
89.6%
|
| 2 | Once | 48 |
2.2%
|
| 3 | Twice | 54 |
2.5%
|
| 4 | 3-5 times | 45 |
2.1%
|
| 5 | 6-10 times | 25 |
1.1%
|
| 6 | 11-20 times | 13 |
0.6%
|
| 7 | More than 20 times | 28 |
1.3%
|
| 8 | Not applicable | 9 |
0.4%
|
| Sysmiss | 6 |