1968

7.1

1961

5.7

1954

3.0

1951

6.5

1965

7.8

1967

6.9

1957

7.0

1960

6.5

1963

5.9

1965

7.2

1962

6.9

1955

5.8

1958

6.3

1964

8.0

1959

8.4

1953

3.8

1959

5.0