1986

4.1

1988

4.0

1987

5.2

1991

6.0

1985

0.0

2001

7.2

2000

7.6

1990

4.8

1995

6.4

1997

4.2

1994

7.8

1996

6.2

2009

6.7

1989

6.1

1984

7.3

1990

6.3

1983

5.5

1998

5.4

1972

7.9

1989

6.8

2005

7.7

1987

6.0

2010

8.0

1992

6.7

1991

5.3

1995

7.8

1984

7.2

1983

7.5

2005

6.3

1986

6.3

1985

7.7

1989

6.7

2001

5.1

1994

6.0