1987

6.5

1990

7.7

2016

7.5

1982

6.4

2012

7.2

2011

7.0

1999

8.0

1968

6.3

1995

6.8

1952

7.2

1987

6.7

2010

5.8

1946

7.6

2009

4.8

1986

6.3

2013

6.8

2009

8.7

1993

6.1

2007

7.2