2005

6.5

1997

5.7

2002

6.2

2001

6.8

1978

6.3

1988

6.2

1928

0.0

1998

6.8

1998

7.1

1993

6.0

1982

5.2

1988

6.6

2005

5.4

2006

5.4

1993

6.7

1983

6.2

2004

7.2

2008

5.7

1971

7.1

1988

6.2