| Value | Category | Cases | |
|---|---|---|---|
| 1 | Last month | 60 |
9.5%
|
| 2 | 1-6 months ago | 103 |
16.3%
|
| 3 | 6-12 months ago | 136 |
21.6%
|
| 4 | More than a year ago | 331 |
52.5%
|
| 9 | Missing | 1 |
0.2%
|
| Sysmiss | 552 |