2003

5.7

1995

5.4

2009

7.1

2011

6.7

2013

5.9

1992

7.3

2014

6.1

2012

7.0

2013

6.1

2002

6.4

1983

6.1

1975

8.0

2007

5.6

2008

6.3

1961

7.2

1998

6.8

2010

7.8

2007

7.7

2003

6.3

1977

6.7