2000

7.6

1996

7.5

1951

7.1

2004

6.4

2007

6.5

2008

6.2

2002

7.0

2008

6.6

2001

2.0

2003

6.3

1992

6.6

1970

7.5

1988

7.2

2003

7.3

2004

6.3

1969

6.7

1987

7.3

1997

6.0

2002

6.2

2014

6.7