1973

3.5

1992

7.4

1970

3.7

1999

7.5

2001

7.4

1991

5.7

2006

7.4

2007

6.5

2006

6.3

1996

7.0

1973

5.0

2023

0.0

1995

4.7

1980

4.8

1991

4.7

1930

6.8

2004

6.7

2012

6.0

1976

5.7

1982

6.3