| Value | Category | Cases | |
|---|---|---|---|
| 1 | Last month | 0 |
0%
|
| 2 | 1-6 months ago | 8 |
4.1%
|
| 3 | 6-12 months ago | 20 |
10.3%
|
| 4 | More than a year ago | 149 |
76.8%
|
| 9 | Missing | 17 |
8.8%
|
| Sysmiss | 989 |