2005

6.5

1996

6.4

1987

7.5

1988

7.9

1979

6.5

1982

7.5

1984

6.6

2001

7.2

1986

7.1

1990

6.3

1989

5.7

1991

7.0

1994

6.5

1996

7.3

1998

6.4

2002

6.3

1984

7.7

2007

5.2

1979

8.2

2004

5.9