| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 3 months | 41 |
2.1%
|
| 2 | 3 to 6 months | 21 |
1.1%
|
| 3 | 6 to 12 months | 140 |
7.2%
|
| 4 | More than a year | 1730 |
89.5%
|
| Sysmiss | 539 |