| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 372 |
76.1%
|
|
| 1991 | 16 |
3.3%
|
|
| 1992 | 12 |
2.5%
|
|
| 1993 | 21 |
4.3%
|
|
| 1994 | 15 |
3.1%
|
|
| 1995 | 20 |
4.1%
|
|
| 1996 | 15 |
3.1%
|
|
| 1997 | 18 |
3.7%
|
|
| Sysmiss | 432 |