1976

7.0

1968

6.9

1970

7.7

2020

6.9

1958

6.9

1997

6.8

1955

7.2

2008

9.0

1995

7.8

2007

7.1

2001

4.3

2008

7.2

1965

6.4

2006

7.4

1974

6.5

1972

6.7

1989

5.5

1984

6.7

1921

6.6

1967

6.5