1997

6.8

2000

7.1

2006

7.4

2006

7.5

2002

7.0

2001

6.4

1973

6.1

1952

7.4

2001

6.3

2007

6.1

1943

6.7

2023

7.7

2005

6.9

2008

6.2

2004

7.0

1952

5.9

1969

6.9

1975

7.3

1930

3.5

1983

6.7