Year	Percent
2005-01-01	57.7
2006-01-01	58.1
2007-01-01	58.3
2008-01-01	58.1
2009-01-01	56.4
2010-01-01	56.0
2011-01-01	56.1
2012-01-01	56.2
2013-01-01	56.2
2014-01-01	56.5
2015-01-01	56.8
2016-01-01	57.3