2004

6.9

1983

6.3

2005

7.1

2006

7.4

2006

7.3

1990

4.0

2001

6.8

1991

5.7

1985

6.7

1987

6.7

1991

7.1

1993

5.7

1989

7.0

1992

6.9

1983

7.2

2008

6.5

1981

6.4

1983

6.9

1985

7.1