2013

6.9

2008

7.7

2014

7.1

2012

7.8

2015

7.3

1977

8.2

1997

7.9

2016

7.6

2016

7.5

1990

7.4

2015

7.9

2011

7.3

2007

7.8

1985

8.3

2015

7.6

1994

8.7

2014

8.5

2009

7.3

2009

6.7

1992

7.7