Year	Percent
2005-01-01	30.8
2006-01-01	30.3
2007-01-01	30.0
2008-01-01	29.5
2009-01-01	29.1
2010-01-01	28.9
2011-01-01	28.7
2012-01-01	28.4
2013-01-01	28.2
2014-01-01	28.0
2015-01-01	27.9
2016-01-01	27.4