2003

5.8

2000

5.5

2005

8.6

2009

6.5

2005

5.6

1979

6.7

2008

7.2

2011

7.1

1932

6.6

1993

6.1

2006

6.3

2000

6.3

1972

6.6

2003

5.6

1999

6.2

2008

5.6

2010

6.8

2007

6.0

1958

7.0

2001

6.0