1992

7.5

1998

5.5

1994

7.9

2003

5.9

1960

6.1

1947

7.4

1994

6.7

2007

6.0

2008

6.7

1949

7.1

1997

7.1

1996

7.0

2002

6.2

1965

5.8

2000

7.6

2004

7.0

1985

6.3

2010

7.0

2006

4.0

1997

6.4