2006

4.6

1999

4.9

1988

3.0

1993

7.1

2004

5.2

1992

5.8

1996

6.2

1995

7.3

1997

4.3

1987

4.6

1987

7.7

2002

7.9

1990

6.4

1988

4.2

1998

4.0