Year Percent 2003-01-01 29.7418 2004-01-01 27.0591 2005-01-01 21.8406 2006-01-01 20.1249 2007-01-01 16.9595 2008-01-01 17.8259 2009-01-01 17.3679 2010-01-01 15.6245 2011-01-01 14.5923 2012-01-01 15.7141 2013-01-01 17.2723 2014-01-01 19.5661 2015-01-01 21.4707 2016-01-01 22.7502 2017-01-01 22.9091