| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 2 |
1.7%
|
|
| 1982 | 2 |
1.7%
|
|
| 1983 | 7 |
6%
|
|
| 1984 | 6 |
5.1%
|
|
| 1985 | 7 |
6%
|
|
| 1986 | 12 |
10.3%
|
|
| 1987 | 7 |
6%
|
|
| 1988 | 12 |
10.3%
|
|
| 1989 | 10 |
8.5%
|
|
| 1990 | 7 |
6%
|
|
| 1991 | 9 |
7.7%
|
|
| 1992 | 7 |
6%
|
|
| 1993 | 9 |
7.7%
|
|
| 1994 | 6 |
5.1%
|
|
| 1995 | 5 |
4.3%
|
|
| 1996 | 5 |
4.3%
|
|
| 1997 | 3 |
2.6%
|
|
| 1999 | 1 |
0.9%
|
|
| Sysmiss | 38601 |