2003

8.0

2007

7.0

2005

7.2

1997

6.6

2005

6.9

1985

7.7

2000

7.6

1996

6.4

2006

6.0

1984

7.2

1959

7.8

2002

7.5

1987

6.5

1999

7.6

1998

8.1

1994

8.3

1976

8.1

1985

8.3