| Value | Category | Cases | |
|---|---|---|---|
| 1992 | 6 |
1.5%
|
|
| 1993 | 28 |
6.9%
|
|
| 1994 | 35 |
8.7%
|
|
| 1995 | 50 |
12.4%
|
|
| 1996 | 92 |
22.8%
|
|
| 1997 | 190 |
47.1%
|
|
| 1998 | 2 |
0.5%
|
|
| Sysmiss | 9953 |