1980

6.1

1986

5.0

1993

7.1

2008

7.6

1981

5.6

1982

7.5

1979

6.8

2001

4.7

1990

0.0

1985

5.0

1995

2.4

1987

6.2

1983

7.5

1984

4.5

1987

2.8