| Value | Category | Cases | |
|---|---|---|---|
| 1 | within the last month | 5 |
10%
|
| 2 | within the last six months | 19 |
38%
|
| 3 | within the last one year | 19 |
38%
|
| 4 | one year ago | 7 |
14%
|
| Sysmiss | Don't know | 0 | |
| Sysmiss | Not applicable | 0 | |
| Sysmiss | Others | 0 | |
| Sysmiss | Can't reveal | 0 | |
| Sysmiss | 4153 |