2001

7.8

1981

7.4

1993

7.0

1984

7.2

2000

7.8

2000

7.3

1982

7.8

1979

7.8

1987

7.3

1990

6.3

1989

6.8

2007

5.6

2008

6.7

2003

5.5

1989

6.3

2003

6.5

2003

5.3

1995

7.1

1988

6.9

1997

6.2