1980

4.7

8.0

1998

0.0

1981

5.6

1979

5.2

1988

6.5

1976

4.8

1989

2.0

1982

7.3

1983

4.6

1977

6.6

1984

7.3

1986

7.9

1985

5.2

1990

6.0

1996

6.0

1978

0.0

1993

8.4

1978

0.0

1977

5.1