Year	Percent
2005-01-01	38.8
2006-01-01	38.9
2007-01-01	39.1
2008-01-01	38.6
2009-01-01	36.8
2010-01-01	36.0
2011-01-01	35.9
2012-01-01	35.9
2013-01-01	36.1
2014-01-01	36.4
2015-01-01	37.0
2016-01-01	37.6