1940

6.1

1940

6.2

1939

6.6

1989

5.8

1970

5.5

2007

4.7

2009

6.1

1982

6.3

2003

5.2

1936

6.2

1972

5.3

1982

6.0

1975

5.0

1997

6.6

1998

7.1

2000

6.4

1996

4.8

2006

5.0

1988

6.6

2001

6.8