1958

6.2

1961

5.6

1965

6.2

1983

5.8

1979

5.7

1963

7.0

1980

5.0

1965

7.5

1984

7.2

1960

6.0

1987

6.0

1986

7.1

1984

7.5

1989

6.7

1973

6.9

1957

6.4

1985

6.7

1991

10.0

1989

3.7

1958

4.5

1982

5.5

1969

5.2

1982

6.2

1963

0.0

1977

7.2

1964

7.2

1968

6.3

1968

5.3

1968

6.5

1987

5.1

1979

2.0