| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know | 2 |
0.3%
|
| -8 | Refused | 1 |
0.2%
|
| -5 | Not applicable | 0 |
0%
|
| -3 | Missing | 12 |
1.9%
|
| 1 | Less than 6 months | 94 |
15.1%
|
| 2 | 6 months or more | 514 |
82.5%
|
| Sysmiss | 29487 |