1984

7.5

1991

6.4

1977

6.0

1971

7.8

1976

7.1

1982

7.2

1993

6.9

1978

7.1

1977

6.8

2005

0.0

1999

7.9

1991

7.0

1975

5.9

1997

6.3

1987

6.0

1972

7.3

2004

6.5

1990

7.4

1989

6.5

1998

7.8