2007

4.7

2013

5.8

2012

6.3

2012

6.8

2006

7.8

2015

6.6

2010

8.1

2008

7.2

2012

6.3

2004

8.0

1997

8.3

2009

7.4

2005

8.3

2002

7.2

2008

4.5