1994

6.6

1989

6.4

2000

6.4

2004

6.7

1995

6.2

1988

6.9

1997

6.2

1996

5.6

1985

7.5

1983

6.6

2004

6.6

1990

6.9

1992

6.8

1986

7.6

2002

6.1

2005

6.2

1988

6.8

2004

7.1

1996

6.4

2006

6.4