| Value | Category | Cases | |
|---|---|---|---|
| 1961 | 4 |
1.9%
|
|
| 1962 | 6 |
2.8%
|
|
| 1963 | 4 |
1.9%
|
|
| 1964 | 6 |
2.8%
|
|
| 1965 | 2 |
0.9%
|
|
| 1966 | 3 |
1.4%
|
|
| 1967 | 6 |
2.8%
|
|
| 1968 | 5 |
2.4%
|
|
| 1969 | 3 |
1.4%
|
|
| 1970 | 8 |
3.8%
|
|
| 1971 | 1 |
0.5%
|
|
| 1972 | 10 |
4.7%
|
|
| 1973 | 6 |
2.8%
|
|
| 1974 | 2 |
0.9%
|
|
| 1975 | 3 |
1.4%
|
|
| 1976 | 3 |
1.4%
|
|
| 1977 | 4 |
1.9%
|
|
| 1978 | 3 |
1.4%
|
|
| 1979 | 6 |
2.8%
|
|
| 1980 | 7 |
3.3%
|
|
| 1981 | 6 |
2.8%
|
|
| 1982 | 7 |
3.3%
|
|
| 1983 | 6 |
2.8%
|
|
| 1984 | 5 |
2.4%
|
|
| 1985 | 8 |
3.8%
|
|
| 1986 | 8 |
3.8%
|
|
| 1987 | 9 |
4.2%
|
|
| 1988 | 5 |
2.4%
|
|
| 1989 | 10 |
4.7%
|
|
| 1990 | 4 |
1.9%
|
|
| 1991 | 6 |
2.8%
|
|
| 1992 | 14 |
6.6%
|
|
| 1993 | 16 |
7.5%
|
|
| 1994 | 10 |
4.7%
|
|
| 1995 | 6 |
2.8%
|