2008

6.8

2008

6.5

1999

5.3

1998

7.1

1997

5.7

2003

6.9

1978

6.3

1991

6.2

1984

6.1

1994

5.2

1996

5.4

1998

6.6

1994

6.7

1967

0.0

2001

6.3

1982

6.8

2003

6.4

2005

6.9

2000

6.4

2006

4.3