2004

6.4

2014

5.9

2011

6.2

2010

7.7

2010

6.3

2012

5.8

1999

7.6

2013

8.4

2003

6.7

2012

6.0

2013

6.8

2000

6.5

2014

6.2

1990

5.8

2004

6.0

1986

6.3

2002

6.6

2001

5.8

2009

6.8

2005

6.9