1950 8
1955 11
1960 13
1961 11
1962 14 
1963 16
1964 17
1965 19
1966 19
1967 19
1968 22
1969 23
1970 22
1971 26
1972 28
1973 30
1974 26
1975 25
1976 29
1977 30
1978 31
1979 31
1980 29
1981 28
1982 27
1983 30
1984 30
1985 32
1986 33
1987 33
1988 34
1989 36
1990 36
1991 35
1992 35
1993 34