1994

5.2

1995

4.9

1998

6.5

1997

5.1

2006

5.1

2008

6.8

1993

6.6

1999

4.2

2002

6.9

1996

6.5

1991

7.0

1997

5.9

1990

2.8

2010

7.7

2000

6.2

1993

0.0

2001

6.6