| Value | Category | Cases | |
|---|---|---|---|
| 1 | less than a month | 173 |
47.4%
|
| 2 | 1-2 months | 152 |
41.6%
|
| 3 | 2-3 months | 27 |
7.4%
|
| 4 | more than 3 months | 13 |
3.6%
|
| Sysmiss | 4279 |