Year	Percent
2004-01-01	12.0
2005-01-01	11.7
2006-01-01	11.3
2007-01-01	10.8
2008-01-01	11.5
2009-01-01	14.3
2010-01-01	15.0
2011-01-01	14.9
2012-01-01	14.6
2013-01-01	14.2
2014-01-01	12.8
2015-01-01	11.5
2016-01-01	10.6