| Value | Category | Cases | |
|---|---|---|---|
| 0 | 8239 |
2.6%
|
|
| 3 | May | 91298 |
28.6%
|
| 6 | June | 79192 |
24.8%
|
| 9 | September | 66174 |
20.8%
|
| 12 | December | 73851 |
23.2%
|
| Sysmiss | 4 |