1990

7.4

1989

5.1

1988

3.7

1990

3.9

1980

3.7

2005

6.9

1989

0.0

1981

4.2

1986

7.1

1985

3.9

1988

6.5

2009

5.5

1980

6.0

1979

7.1

2010

7.5

1993

8.1

1975

7.0