1993

5.6

2014

7.1

2017

6.7

2013

7.1

2016

7.1

2000

6.0

1966

7.6

1998

7.2

2010

7.1

2008

7.1

2014

8.3

2016

6.5

2016

6.8

1978

7.8

2017

7.6

2009

7.4

2017

6.2

2003

7.8

2016

9.2

2006

7.7