1982

6.3

1989

6.1

1983

6.0

1980

7.5

1986

7.9

1998

10.0

1994

7.8

1989

5.0

1995

7.3

1989

6.1

1979

6.7

1984

7.4

2006

5.2

1980

7.7

1993

6.7

1985

5.0

1994

5.9