1974

6.4

1990

7.5

1994

7.9

2011

7.1

2011

6.5

1967

7.7

2006

7.0

2017

8.1

2015

7.9

2021

7.4

2005

4.8

1941

8.0

1989

7.1

1993

6.1

2010

6.6

1936

8.3

1955

7.2

1979

7.5

2013

6.1

2009

7.5