1976 6.8

1973 7.5

1973 7.6

1970 7.1

1968 6.8

1968 7.2

1967 7.6

1966 7.2

1965 8.1

1965 6.4

1965 7.2

1964 7.8

1963 7.1

1961 7.3

1959 7.2

1958 7.1

1955 7.3

1953 7.2

1951 7.3

1950 7.3