Year	Percent
2005-01-01	13.8
2006-01-01	12.8
2007-01-01	12.2
2008-01-01	13.4
2009-01-01	17.9
2010-01-01	17.9
2011-01-01	16.9
2012-01-01	16.8
2013-01-01	16.6
2014-01-01	15.5
2015-01-01	14.3
2016-01-01	13.4