1991

5.2

1999

6.5

1970

6.7

1979

5.5

1974

6.2

1980

5.3

1984

7.1

1984

8.4

1982

6.0

1986

5.6

1973

6.9

1982

7.5

1978

6.0

1984

7.2

1992

6.4

1977

4.2

1996

3.6

2002

6.4

1968

5.7

1976

6.2

1975

5.7

1971

5.8

1983

5.7

1998

5.0

1987

7.8

1983

6.5