| Value | Category | Cases | |
|---|---|---|---|
| 1 | within past 2 yrs | 52 |
38.2%
|
| 2 | more than 2 yrs ago | 42 |
30.9%
|
| 3 | never | 34 |
25%
|
| 77 | don't know | 8 |
5.9%
|
| Sysmiss | 993 |