Year Percent 1998-01-01 49.526700000000000 1999-01-01 46.992800000000000 2000-01-01 54.958600000000000 2001-01-01 58.260400000000000 2002-01-01 56.126000000000005 2003-01-01 60.928000000000004 2004-01-01 71.544200000000000 2005-01-01 78.669000000000000 2006-01-01 83.075900000000000 2007-01-01 90.961800000000000 2008-01-01 92.575400000000000 2009-01-01 89.880500000000000 2010-01-01 90.378400000000000 2011-01-01 91.888400000000000 2012-01-01 82.547999999999990 2013-01-01 77.321200000000000 2014-01-01 81.234900000000000 2015-01-01 83.509600000000000 2016-01-01 74.772700000000000