1985

6.2

1978

5.7

1968

1.0

1959

0.0

1983

5.5

1978

7.6

1974

8.0

1968

0.0

1977

6.4

1981

6.7

1988

4.4

1963

5.3

1981

3.5

1981

5.0

1966

5.8