2008

6.6

2007

6.1

2001

6.3

2004

7.0

1969

4.2

1997

6.4

1973

7.5

1971

6.2

2002

6.4

2005

5.8

1993

6.4

1992

6.0

2002

7.1

1997

6.6

1977

6.0

1970

6.4

1982

6.0

1991

6.5

2005

6.1

1976

6.6