| Value | Category | Cases | |
|---|---|---|---|
| 1 | dont know | 34 |
47.9%
|
| 2 | months | 5 |
7%
|
| 3 | years | 32 |
45.1%
|
| 7 | refused | 0 |
0%
|
| 9 | missing | 0 |
0%
|
| Sysmiss | 5820 |