| Value | Category | Cases | |
|---|---|---|---|
| 1 | within the last month | 8 |
7.8%
|
| 2 | within the last six months | 34 |
33%
|
| 3 | within the last one year | 33 |
32%
|
| 4 | one year ago | 28 |
27.2%
|
| Sysmiss | Don't know | 0 | |
| Sysmiss | Not applicable | 0 | |
| Sysmiss | Others | 0 | |
| Sysmiss | Can't reveal | 0 | |
| Sysmiss | 4100 |