| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 18 |
3.1%
|
|
| 1993 | 71 |
12.4%
|
|
| 1994 | 77 |
13.4%
|
|
| 1995 | 99 |
17.2%
|
|
| 1996 | 142 |
24.7%
|
|
| 1997 | 164 |
28.6%
|
|
| 1998 | 3 |
0.5%
|
|
| Sysmiss | 9782 |