| Value | Category | Cases | |
|---|---|---|---|
| 1981 | 14 |
1.4%
|
|
| 1982 | 94 |
9.4%
|
|
| 1983 | 102 |
10.2%
|
|
| 1984 | 108 |
10.8%
|
|
| 1985 | 144 |
14.4%
|
|
| 1986 | 109 |
10.9%
|
|
| 1987 | 126 |
12.6%
|
|
| 1988 | 106 |
10.6%
|
|
| 1989 | 114 |
11.4%
|
|
| 1990 | 82 |
8.2%
|