| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 38 |
5.5%
|
|
| 1993 | 82 |
11.8%
|
|
| 1994 | 83 |
11.9%
|
|
| 1995 | 121 |
17.4%
|
|
| 1996 | 172 |
24.7%
|
|
| 1997 | 198 |
28.4%
|
|
| 1998 | 3 |
0.4%
|
|
| Sysmiss | 9659 |