1996

6.4

1997

7.2

2009

8.0

1998

8.2

2001

7.2

2000

7.6

2003

5.3

1994

7.8

1995

7.3

1990

7.4

2006

6.7

1993

7.5

1997

6.0

2008

8.4

2001

7.8

2002

6.8

2005

7.5

2002

7.3