| Value | Category | Cases | |
|---|---|---|---|
| 1990 | 399 |
82.1%
|
|
| 1991 | 16 |
3.3%
|
|
| 1992 | 13 |
2.7%
|
|
| 1993 | 20 |
4.1%
|
|
| 1994 | 15 |
3.1%
|
|
| 1995 | 14 |
2.9%
|
|
| 1996 | 4 |
0.8%
|
|
| 1997 | 5 |
1%
|
|
| Sysmiss | 435 |