2011

7.1

7.3

1972

6.4

1986

7.0

2006

6.4

1987

5.5

2005

7.4

2008

7.8

2017

6.0

2008

6.9

1922

7.2

2007

5.7

2010

4.4

1991

6.2

1969

7.0

1981

5.6

1987

6.3

1992

5.6

2007

5.4

2009

4.5