Year Percent 1998-01-01 89.4000 1999-01-01 67.2000 2000-01-01 58.6000 2001-01-01 58.6000 2002-01-01 58.6000 2003-01-01 58.6000 2004-01-01 58.6000 2005-01-01 65.5000 2006-01-01 93.9000 2007-01-01 86.1000 2008-01-01 81.4000 2009-01-01 68.7000 2010-01-01 70.6397 2011-01-01 76.2223 2012-01-01 77.9143 2013-01-01 78.2960 2014-01-01 69.5075 2015-01-01 69.3468 2016-01-01 72.4512