2006

6.7

2008

7.6

2004

7.3

2012

5.8

2002

5.5

1980

8.4

2009

6.8

2014

7.5

2010

7.0

1995

7.3

2020

5.2

2012

6.2

2009

8.2

2010

6.4

2015

6.3

2011

6.5

2002

8.4

2003

8.5

1953

6.6

1991

6.5