Year	Percent
2004-01-01	67
2005-01-01	59.8
2006-01-01	40.4
2007-01-01	42.5
2008-01-01	42.8
2009-01-01	51.3
2010-01-01	52.7
2011-01-01	51.8
2012-01-01	55.4
2013-01-01	65.2
2014-01-01	67.1
2015-01-01	70.8