| Value | Category | Cases | |
|---|---|---|---|
| 1 | Never | 2006 |
91.7%
|
| 2 | Once | 30 |
1.4%
|
| 3 | Twice | 38 |
1.7%
|
| 4 | 3-5 times | 40 |
1.8%
|
| 5 | 6-10 times | 19 |
0.9%
|
| 6 | 11-20 times | 15 |
0.7%
|
| 7 | More than 20 times | 24 |
1.1%
|
| 8 | Not applicable | 10 |
0.5%
|
| Sysmiss | 6 |