1980

4.8

1933

6.6

1917

5.5

1922

6.1

1920

6.7

1922

7.2

1922

6.5

1921

6.8

1966

5.0

2006

7.5

1925

5.0

2008

6.4

1919

6.3

1979

5.8

2006

6.6

2002

6.9

2006

7.2

1934

5.4

2000

5.6

1991

4.2