| Value | Category | Cases | |
|---|---|---|---|
| 1 | Within past month | 966 |
51.5%
|
| 2 | Within past 3 months | 456 |
24.3%
|
| 3 | Within 6 months | 193 |
10.3%
|
| 4 | More than 6 months ago | 261 |
13.9%
|
| Sysmiss | 10604 |