1998

6.7

2011

6.9

1987

6.3

1931

7.2

1957

7.5

1938

7.1

2009

5.8

1979

4.7

1963

7.5

1982

5.8

1952

6.3

1915

6.0

1967

7.0

1968

7.4

1960

8.3

1978

7.4

2008

7.1

1937

7.2

1955

7.9

1997

6.5