Year Percent 2000-01-01 61.5127656788439 2001-01-01 62.2052019832103 2002-01-01 63.4055520529072 2003-01-01 63.0346024751476 2004-01-01 63.7670447926386 2005-01-01 63.7477536539311 2006-01-01 63.9732132447794 2007-01-01 64.1452068100399 2008-01-01 63.9557018915650 2009-01-01 63.0171000436665 2010-01-01 63.3878772302712 2011-01-01 63.9148390485728 2012-01-01 64.3436864813416 2013-01-01 64.6272682371432 2014-01-01 65.5662121309469 2015-01-01 65.9098049668321 2016-01-01 66.0756644418832 2017-01-01 66.6292640510155