2006

6.0

2003

7.6

2005

6.5

2008

6.8

2008

6.1

2006

7.4

1999

6.6

1980

6.3

1980

5.6

2004

6.7

1981

6.7

1988

7.1

1986

7.0

2002

3.7

1993

6.2

1990

6.7

2003

6.9

1996

5.5

1991

6.2

1992

6.3