| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than one month ago | 15 |
3.6%
|
| 2 | 1 to 6 months ago | 45 |
10.7%
|
| 3 | 6 to 12 months ago | 88 |
20.9%
|
| 4 | More than one year ago | 273 |
64.8%
|
| Sysmiss | 2771 |