Year Percent 1996-01-01 91.3159 1997-01-01 87.6040 1998-01-01 87.6040 1999-01-01 87.6040 2000-01-01 100.0000 2001-01-01 100.0000 2002-01-01 100.0000 2003-01-01 100.0000 2004-01-01 100.0000 2005-01-01 100.0000 2006-01-01 99.7229 2007-01-01 98.8228 2008-01-01 100.0000 2009-01-01 100.0000 2010-01-01 100.0000 2011-01-01 98.6083 2012-01-01 98.4266 2013-01-01 97.6488 2014-01-01 97.0133 2015-01-01 96.5901 2016-01-01 95.7927