1990

6.9

2015

6.9

2008

7.6

2004

8.3

2007

7.4

2011

7.0

2002

7.4

2014

6.8

2015

7.3

1957

7.7

1998

7.3

2011

6.3

2010

8.0

2019

8.1

2006

7.1

2010

7.5

1994

6.5

2012

6.8

1963

5.7

2013

7.0