2001

8.3

1993

5.6

1983

8.0

2001

4.8

2014

8.2

2016

7.0

2004

7.1

2017

6.7

2010

7.7

1981

6.0

2009

7.9

1973

6.8

2003

8.1

2000

7.5

2004

7.9

2013

8.2

2006

7.6

1998

6.8

2015

7.8

2018

7.0