1981

6.5

1989

5.6

1971

4.6

1971

5.6

1972

7.2

1983

6.1

1984

5.3

1970

6.5

1979

6.7

1980

6.2

1972

5.0

1988

8.1

1980

6.7

1961

7.7

1979

1.3

1973

6.1

1976

6.9

1967

7.8

1984

5.7

1997

6.4

1965

6.4

1981

0.0