| Value | Category | Cases | |
|---|---|---|---|
| 1 | within past 2 yrs | 64 |
55.2%
|
| 2 | more than 2 yrs ago | 24 |
20.7%
|
| 3 | never | 23 |
19.8%
|
| 77 | don't know | 5 |
4.3%
|
| Sysmiss | 1527 |