Year	Percent
2005-01-01	16.3504521847818
2006-01-01	15.7935931838206
2007-01-01	16.2022996160278
2008-01-01	16.5659968967759
2009-01-01	17.3191661192465
2010-01-01	17.5521354237568
2011-01-01	17.6383745811362
2012-01-01	17.2799942405851
2013-01-01	17.5625847062154
2014-01-01	17.7949990238052
2015-01-01	18.0377982985786
2016-01-01	18.1550614869834
2017-01-01	18.2216133059031