1971

7.3

1955

6.6

1948

6.0

1969

7.1

1964

7.2

1968

6.8

1967

6.6

1966

6.2

1951

7.5

1963

7.1

1961

7.2

1947

6.7

1960

6.0

1965

6.1

1950

6.2

1951

6.6

1972

6.4

1973

6.8

1970

6.1

1959

5.0

1968

6.1

1967

6.2

1953

5.5

1967

7.0

1954

4.8

1962

6.1

1957

6.4

1949

6.8

1964

6.1