1965

6.7

2007

6.5

2006

7.2

2007

6.2

2008

6.5

2009

8.2

2002

5.2

1978

6.2

2014

6.0

2007

5.0

1956

7.7

1969

7.9

2001

4.9

1997

4.6

1935

6.8

0.0

2004

7.8

1993

7.7

2013

6.2

2005

7.4