1969

6.1

1975

5.4

1967

6.5

1970

5.7

1968

6.4

1968

5.8

1978

4.8

1977

6.0

1979

5.3

1965

0.0

1974

5.3

1966

5.6

1973

5.9

1962

7.4

1977

6.0

1998

7.8