1959

8.1

2009

7.6

1994

8.7

1994

8.3

2012

7.8

2006

7.4

1999

8.0

2008

7.7

2014

7.8

2014

8.5

2012

7.2

2008

8.5

2010

8.4

2017

7.9

1994

8.5

2014

7.7

2001

8.5

2013

6.5

2015

7.3

1971

8.2