| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 2 |
15.4%
|
|
| 1993 | 6 |
46.2%
|
|
| 1994 | 3 |
23.1%
|
|
| 7777 | 2 |
15.4%
|
|
| Sysmiss | 9616 |