1987

7.3

1982

6.1

1981

8.5

1980

7.0

1980

5.0

1986

6.8

1992

6.7

1986

6.6

1990

6.3

1985

6.4

1984

6.2

1987

3.5

1990

6.8

1990

7.0

1984

6.0

1989

6.0

1979

0.0

1983

6.8