Year Percent 1999-01-01 84.0207 2000-01-01 57.8000 2001-01-01 69.0000 2002-01-01 71.3552 2003-01-01 73.9669 2004-01-01 75.6918 2005-01-01 77.0447 2006-01-01 73.8452 2007-01-01 71.9639 2008-01-01 63.2649 2009-01-01 70.9442 2010-01-01 74.0521 2011-01-01 75.1607 2012-01-01 80.0794 2013-01-01 81.1136 2014-01-01 82.8471 2015-01-01 78.8748 2016-01-01 74.5424