1957

6.2

1987

7.2

1997

5.0

1988

6.3

1980

6.1

2011

6.3

1983

7.8

1984

0.0

1989

6.0

1990

7.3

1997

7.3

1998

7.6

2009

8.0

1955

5.5

1971

8.1

1984

6.6

2006

8.2

1957

5.7

1993

3.5

1978

6.3

1992

0.0

1985

5.0

1998

8.1

1991

5.7

1976

6.8

1982

2.8

1990

1.7

1951

7.9

2014

7.9

1980

0.0

1991

8.0

1991

7.4

1972

7.9

1982

6.2

1998

5.0

1984

7.5

1986

4.7

1959

7.1

1999

5.3

1983

6.8

1986

4.3

1989

8.3

1985

6.5

2011

8.2

1981

6.7

1956

7.3

2000

3.0

1959

5.5

1986

5.9

1976

4.9

2000

5.2

1977

6.3

2008

8.4

1982

5.0

1980

6.7

1982

8.0

1999

8.3

1986

6.8

1987

1.0

1998

5.3

1978

7.0

1990

6.1