| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 12 months ago | 18 |
12.4%
|
| 2 | 12-23 months ago | 13 |
9%
|
| 3 | 2 or more years ago | 107 |
73.8%
|
| 9 | Missing | 7 |
4.8%
|
| Sysmiss | 4500 |