2013

7.5

2011

6.5

2010

7.1

2007

7.8

2016

6.7

2005

7.7

2006

5.8

2004

7.3

2018

6.5

2010

8.2

2014

7.9

1998

8.2

2006

8.2

2001

7.8

1991

7.1

2008

7.7

2009

7.3

2012

5.9

2015

7.5