Year Percent 2000-01-01 75.601 2001-01-01 64.470 2002-01-01 52.910 2003-01-01 57.920 2004-01-01 62.370 2005-01-01 72.140 2006-01-01 76.820 2007-01-01 73.890 2008-01-01 61.930 2009-01-01 73.990 2010-01-01 81.980 2011-01-01 88.680 2012-01-01 95.720 2013-01-01 98.110 2014-01-01 97.890 2015-01-01 98.800 2016-01-01 95.290