1955

2.4

2004

5.8

2005

5.2

2007

6.8

1957

6.7

1953

7.2

1971

4.5

2010

6.8

2008

6.4

1927

5.0

1916

6.7

2013

4.4

2002

6.9

2000

5.3

1918

6.0

2014

7.4

1986

7.0

2009

7.2

1933

5.7

2008

6.1