| Value | Category | Cases | |
|---|---|---|---|
| 1 | Month and year | 851 |
76.9%
|
| 2 | From calendar | 0 |
0%
|
| 5 | Year | 232 |
21%
|
| 6 | Not coded | 0 |
0%
|
| 7 | Month | 3 |
0.3%
|
| 8 | None | 20 |
1.8%
|
| Sysmiss | 6879 |