1975

0.0

1981

5.2

1972

4.0

1997

0.0

1978

7.2

1981

5.7

1982

5.1

1979

5.0

1999

5.1

1980

6.7

1971

6.5

1979

7.3

1981

1.4

1986

6.8

1971

6.5

1979

4.4

1972

6.3

1976

5.3

1976

7.6

1971

4.3

1982

4.2

1996

6.1

1980

2.0

1976

4.5

1980

6.1

1971

6.1

1977

6.2

1973

6.0

1972

7.1

1976

4.2

1972

3.5

1994

5.3

1972

6.0

1981

6.9

1975

5.6

1971

7.8

1992

6.5