| Value | Category | Cases | |
|---|---|---|---|
| 1 | Month and year | 1366 |
93.6%
|
| 5 | Year - a, m imp | 78 |
5.3%
|
| 7 | Month - a, y imp | 5 |
0.3%
|
| 8 | None - all imp | 11 |
0.8%
|
| Sysmiss | 12919 |