| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 78 |
21.3%
|
|
| 1991 | 15 |
4.1%
|
|
| 1992 | 28 |
7.6%
|
|
| 1993 | 32 |
8.7%
|
|
| 1994 | 83 |
22.6%
|
|
| 1995 | 52 |
14.2%
|
|
| 1996 | 48 |
13.1%
|
|
| 1997 | 31 |
8.4%
|
|
| Sysmiss | 554 |