Year	Percent
2005-01-01	70.8917239826450
2006-01-01	71.7710326508733
2007-01-01	72.0246853026193
2008-01-01	72.0879111426326
2009-01-01	72.6018021107892
2010-01-01	72.3408616176179
2011-01-01	72.7828478204060
2012-01-01	73.6136261942524
2013-01-01	73.7293154049499
2014-01-01	73.1056029822863
2015-01-01	73.5342517137651
2016-01-01	73.6820518508333
2017-01-01	73.5016207104331