2001

7.8

1998

6.5

1997

6.5

2006

5.9

2005

8.2

1996

6.1

2008

7.6

1996

6.4

1999

8.4

2012

6.6

1995

6.6

1997

7.1

2007

7.9

1992

6.7

2001

6.8