| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 165 |
75.3%
|
|
| 1991 | 8 |
3.7%
|
|
| 1992 | 8 |
3.7%
|
|
| 1993 | 9 |
4.1%
|
|
| 1994 | 9 |
4.1%
|
|
| 1995 | 11 |
5%
|
|
| 1996 | 6 |
2.7%
|
|
| 1997 | 3 |
1.4%
|
|
| Sysmiss | 702 |