1984

4.6

2007

6.0

1972

6.2

1980

8.2

1964

7.3

2004

7.5

1975

7.8

1992

7.4

1985

7.7

1998

8.1

2000

7.8

2000

6.3

1998

7.8

1932

7.8

1993

7.6

2005

4.5

1976

7.4

1999

7.1

2006

5.6

2001

7.8