1999

7.2

1957

8.5

1979

8.2

1989

7.8

2006

8.2

1996

7.9

1997

7.6

2004

7.2

1985

8.3

1983

8.2

1994

8.5

1988

7.8

1988

7.5

1995

8.4

2001

7.5

1998

8.1

1995

7.6

1989

8.3

2000

8.2

1993

8.6