| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 5 |
1.5%
|
|
| 1993 | 20 |
5.9%
|
|
| 1994 | 32 |
9.4%
|
|
| 1995 | 48 |
14.1%
|
|
| 1996 | 75 |
22.1%
|
|
| 1997 | 158 |
46.5%
|
|
| 1998 | 2 |
0.6%
|
|
| Sysmiss | 10016 |