1975

4.8

1985

6.8

1986

5.1

1979

5.0

1971

8.1

1977

6.7

1989

3.6

1990

3.4

1979

6.2

1968

6.7

1993

5.0

1989

3.5

1971

7.1

1992

6.2

1976

6.0

1978

4.9

1974

7.0

1976

6.2