| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once | 806 |
12.5%
|
| 2 | Twice | 572 |
8.8%
|
| 3 | Three times or more | 484 |
7.5%
|
| 98 | Don't know | 78 |
1.2%
|
| 99 | Not applicable | 4527 |
70%
|
| Sysmiss | 35545 |