| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 2 |
0.9%
|
|
| 1985 | 1 |
0.4%
|
|
| 1988 | 1 |
0.4%
|
|
| 1989 | 3 |
1.3%
|
|
| 1990 | 6 |
2.6%
|
|
| 1991 | 1 |
0.4%
|
|
| 1992 | 5 |
2.1%
|
|
| 1993 | 21 |
8.9%
|
|
| 1994 | 59 |
25.1%
|
|
| 1995 | 85 |
36.2%
|
|
| 1996 | 42 |
17.9%
|
|
| 1997 | 9 |
3.8%
|
|
| Sysmiss | 15025 |