1995

5.9

2003

7.1

1998

4.4

2005

6.3

1988

6.1

1990

6.6

1996

6.5

1997

5.2

2004

5.3

1989

5.7

2002

5.1

1986

6.2

1979

6.7

2006

7.6

2001

7.0

1993

6.8

2005

6.9

1985

6.6

2004

6.8

2006

4.3