Year	Percent
2005-01-01	13.3
2006-01-01	12.5
2007-01-01	11.9
2008-01-01	12.7
2009-01-01	16.5
2010-01-01	16.7
2011-01-01	16.3
2012-01-01	16.3
2013-01-01	16.2
2014-01-01	15.1
2015-01-01	13.9
2016-01-01	13.0