1991

6.8

1971

4.5

2014

4.3

2010

4.0

1918

6.0

2011

6.0

1962

5.7

2006

7.5

2010

7.3

2002

2.9

2013

4.4

2010

5.7

2004

7.2

1995

6.2

1987

6.5

1948

6.1

1946

7.3

1908

5.5

2011

5.0

2008

5.9