1972

6.3

1969

5.2

1977

0.0

1992

7.4

1980

6.1

1975

8.0

1990

6.0

1976

5.8

1994

7.2

1977

4.1

1998

7.0

1985

3.8

1975

7.5

1983

6.8

1984

6.0

1980

6.2