Year Percent 1993-01-01 99.7079 1994-01-01 99.8379 1995-01-01 97.8799 1996-01-01 97.6093 1997-01-01 98.3097 1998-01-01 99.9478 1999-01-01 95.9868 2000-01-01 99.9452 2001-01-01 99.6543 2002-01-01 99.6429 2003-01-01 99.7940 2004-01-01 99.9585 2005-01-01 99.9899 2006-01-01 99.9929 2007-01-01 99.9950 2008-01-01 99.9966 2009-01-01 99.9972 2010-01-01 99.9952 2011-01-01 99.9940 2012-01-01 99.9948 2013-01-01 99.9929 2014-01-01 99.9897 2015-01-01 99.9776 2016-01-01 99.9669