2000

8.2

2000

7.4

2000

6.0

2007

6.4

1987

4.1

2006

6.7

1981

7.2

1982

7.5

2003

7.2

1985

6.6

2002

6.6

1998

6.6

1992

7.4

1996

6.5

1986

6.3

1997

5.7

2009

6.2

2003

6.1

1998

5.7

1975

6.7