1940

6.5

2006

4.5

2021

6.1

1998

6.0

1972

3.0

2009

7.5

2010

6.0

2003

5.5

1993

7.2

1973

4.0

1999

6.5

1985

7.0

1976

7.4

2006

5.6

2013

5.5

1975

7.8

2001

4.8

2013

5.1

2006

6.9

2007

6.1