2014

8.5

1998

7.8

1992

8.1

2007

7.6

2001

7.8

2002

8.4

1991

8.3

1989

7.2

1971

8.2

2009

8.0

2003

8.0

1980

7.9

1943

8.2

1998

8.1

1968

7.8

2013

7.7

2008

8.5

1993

7.5

1976

7.3

2016

7.4