Year	Percent
2005-01-01	56.0
2006-01-01	56.5
2007-01-01	56.8
2008-01-01	56.7
2009-01-01	55.2
2010-01-01	54.9
2011-01-01	55.1
2012-01-01	55.1
2013-01-01	55.1
2014-01-01	55.4
2015-01-01	55.7
2016-01-01	56.2