| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 1 |
5.9%
|
|
| 1993 | 1 |
5.9%
|
|
| 1995 | 5 |
29.4%
|
|
| 1996 | 4 |
23.5%
|
|
| 1997 | 6 |
35.3%
|
|
| Sysmiss | 9748 |