Year Percent 1999-01-01 82.3858 2000-01-01 79.2000 2001-01-01 88.0000 2002-01-01 85.4161 2003-01-01 93.0814 2004-01-01 88.1053 2005-01-01 73.1735 2006-01-01 74.8712 2007-01-01 75.1584 2008-01-01 58.9603 2009-01-01 65.8212 2010-01-01 62.6241 2011-01-01 63.4941 2012-01-01 63.9541 2013-01-01 56.5437 2014-01-01 68.2679 2015-01-01 65.8791 2016-01-01 63.8615