2006

5.8

1997

6.8

1996

5.3

1970

6.1

2007

6.5

2008

6.9

2013

6.3

2003

6.5

1993

6.0

1992

6.3

2011

7.0

1988

7.6

2002

6.7

1995

6.2

1932

6.2

1938

5.7

1999

5.3

2010

5.5

2007

6.5

2004

6.2