1959

8.1

1982

6.4

1990

7.5

1953

6.9

1998

6.1

1938

7.4

1926

7.9

1940

8.3

1952

7.3

2009

5.6

1976

6.7

1986

6.2

1966

6.9

2001

5.6

1946

6.5

1977

5.6

1969

6.7

1988

5.6

1948

5.8

2004

6.8