1990

6.1

2011

6.5

1997

6.1

2013

6.2

2016

4.5

1996

6.0

2002

8.3

1993

5.0

2014

7.6

2006

5.6

2007

7.5

2011

6.3

2009

7.2

2008

6.2

2011

6.6

2004

5.7

2006

7.4

2005

7.1

2012

6.0

2003

5.1