| Value | Category | Cases | |
|---|---|---|---|
| 1 | Within past month | 958 |
19.8%
|
| 2 | Within past 3 months | 1285 |
26.6%
|
| 3 | Within 6 months | 1072 |
22.2%
|
| 4 | More than 6 months ago | 1512 |
31.3%
|
| Sysmiss | 7653 |