| Value | Category | Cases | |
|---|---|---|---|
| 1 | About one month | 2 |
11.1%
|
| 2 | Few months (2-3 months) | 0 |
0%
|
| 3 | Less than one year | 2 |
11.1%
|
| 4 | More than one year | 14 |
77.8%
|
| Sysmiss | 64 |