2010

7.7

1975

8.2

1998

7.2

2005

8.3

2015

7.6

2011

8.3

1976

7.4

2010

8.0

2009

7.0

2016

7.7

2002

6.2

1983

8.0

2012

6.3

2013

7.6

2017

6.5

2007

7.9

2008

7.6

1981

7.9

1988

8.1

2007

7.2