Year Percent 2004-01-01 37.4229 2005-01-01 39.8900 2006-01-01 44.4809 2007-01-01 44.1451 2008-01-01 48.7398 2009-01-01 57.3163 2010-01-01 56.4493 2011-01-01 58.4895 2012-01-01 64.1055 2013-01-01 64.7833 2014-01-01 67.0831 2015-01-01 72.3439 2016-01-01 75.9581