| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know | 0 |
0%
|
| -8 | Refused | 0 |
0%
|
| -5 | Not applicable | 0 |
0%
|
| -3 | Missing | 0 |
0%
|
| 1 | Less than 6 months | 4 |
20%
|
| 2 | 6 months or more | 16 |
80%
|
| Sysmiss | 979 |