1963

5.2

1976

5.5

1989

4.8

1980

6.0

1975

6.1

1974

5.4

1973

6.0

1972

7.9

1992

4.9

1978

6.5

1983

6.9

1974

4.5

1977

7.8

1972

5.7

1966

5.6