2005

8.3

2000

7.6

2014

7.8

2011

7.4

2007

7.5

2017

6.6

2008

7.6

1963

5.7

2015

6.8

1987

5.6

1999

7.9

2012

6.5

1973

6.8

1993

7.9

1998

7.4

2016

7.3

2010

8.1

2004

7.9

2015

7.0

2004

7.9