1990

6.1

1956

7.1

1952

6.7

2001

4.9

2012

6.3

1991

4.7

2010

6.7

2015

6.0

1980

7.1

1968

6.6

2005

5.1

2008

7.5

2009

7.5

2006

4.2

1972

7.4

2011

6.9

1989

7.3

1976

4.5

2005

6.5

1942

6.8