1997

6.4

2009

6.7

2011

6.0

1996

5.9

2014

6.1

2015

6.7

2009

5.6

2010

5.8

2008

5.7

2001

6.2

2016

6.6

2013

6.3

2005

5.5

2016

6.6

2014

7.2

2013

5.7

2007

6.5

2015

5.2

2015

6.9

2014

6.9