1992

8.2

2002

5.3

2012

8.4

1996

8.5

2014

8.3

1998

8.6

2007

8.5

2011

7.7

2007

7.4

2004

7.2

2013

6.6

2016

7.3

1998

7.2

2019

7.8

2018

7.6

2015

7.6

1976

7.0

2017

8.5

2004

8.3

2014

8.6