2003

5.7

1999

5.8

1977

6.7

2006

7.4

2009

7.3

1966

6.7

1998

6.8

2004

6.2

1989

6.2

2010

6.8

2005

5.9

2012

8.2

2012

4.7

1903

6.0

1955

7.2

2013

6.3

1975

6.4

1979

6.7

2000

5.8

1981

6.5