| Value | Category | Cases | |
|---|---|---|---|
| 1976 | 1 |
1.8%
|
|
| 1977 | 1 |
1.8%
|
|
| 1978 | 3 |
5.5%
|
|
| 1980 | 3 |
5.5%
|
|
| 1981 | 2 |
3.6%
|
|
| 1982 | 3 |
5.5%
|
|
| 1983 | 3 |
5.5%
|
|
| 1984 | 3 |
5.5%
|
|
| 1985 | 4 |
7.3%
|
|
| 1986 | 8 |
14.5%
|
|
| 1987 | 1 |
1.8%
|
|
| 1988 | 3 |
5.5%
|
|
| 1989 | 4 |
7.3%
|
|
| 1990 | 5 |
9.1%
|
|
| 1991 | 5 |
9.1%
|
|
| 1992 | 2 |
3.6%
|
|
| 1993 | 2 |
3.6%
|
|
| 1994 | 1 |
1.8%
|
|
| 1995 | 1 |
1.8%
|
|
| Sysmiss | 1376 |