1977

7.2

1989

8.1

2001

5.0

1985

4.1

1983

0.0

1997

7.5

1984

0.0

1978

6.6

1991

6.6

1980

6.9

1977

7.4

1975

7.7

1972

5.8

1990

7.2

1994

6.0