1970

6.1

2013

8.1

2011

8.5

2019

8.7

2008

8.9

2018

8.3

2017

8.4

2016

8.6

2015

8.7

2009

7.9

2010

8.1

1994

8.4

2013

8.5

1989

8.0

2001

8.6

2002

8.6

2010

8.5

2013

8.7

2006

8.2

1989

8.2