1969

7.6

2013

6.8

2006

5.1

1991

7.3

2014

6.6

1997

8.4

2004

8.0

2010

7.0

1928

8.0

2009

7.5

1935

7.5

1972

7.5

2013

7.4

2001

7.4

2013

6.6

1997

7.5

2009

6.4

2005

7.8

2001

7.9

1990

7.3