Year	Percent
2005-01-01	30.4
2006-01-01	29.8
2007-01-01	29.7
2008-01-01	29.5
2009-01-01	29.6
2010-01-01	29.6
2011-01-01	29.5
2012-01-01	29.3
2013-01-01	29.1
2014-01-01	29.0
2015-01-01	28.8
2016-01-01	28.4