Year	Percent
2005-01-01	20.0
2006-01-01	19.8
2007-01-01	19.8
2008-01-01	19.8
2009-01-01	20.3
2010-01-01	20.6
2011-01-01	20.7
2012-01-01	20.6
2013-01-01	20.6
2014-01-01	20.5
2015-01-01	20.4
2016-01-01	20.1