1978

9.2

2008

8.9

2016

8.6

2009

7.9

2013

8.7

2010

8.1

2013

8.1

1989

8.0

2005

8.2

1994

8.4

2004

8.6

2002

8.3

2015

8.2

2019

8.7

2003

7.5

2011

8.5

2013

8.0

2020

8.2

2005

8.1

2010

8.0