| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. Month/year | 4508 |
99.9%
|
| 6 | 6. NOT APPLICABLE | 0 |
0%
|
| 8 | 8. Don't know | 6 |
0.1%
|
| 9 | 9. Missing | 0 |
0%
|
| Sysmiss | 12810 |