1971

7.3

1975

6.0

1964

6.5

1965

6.3

1962

6.1

1967

6.5

1965

6.7

1972

7.1

1980

8.3

1979

6.4

1971

6.3

1965

5.6

1960

5.7

1966

6.3

1970

5.5

1963

7.0

1984

7.1

1972

6.2