Year Percent 2005-01-01 26.8401670091362 2006-01-01 26.6722982797032 2007-01-01 27.4555927417486 2008-01-01 28.5955851617364 2009-01-01 28.6977981360015 2010-01-01 32.0762485878136 2011-01-01 34.0259533306138 2012-01-01 34.6500070629642 2013-01-01 35.2766710150320 2014-01-01 35.9440552794883 2015-01-01 35.9839673047838 2016-01-01 35.9136872689680 2017-01-01 36.3632115109300