2006

7.4

2008

7.7

2012

6.6

2014

6.9

2008

6.2

2011

7.9

1973

7.0

2007

7.5

1969

6.7

2001

8.0

2009

7.4

2006

8.2

2006

7.8

2009

7.3

2016

7.2

2015

7.1

2005

8.2

1980

6.5

2003

8.1

2011

7.1