Year Percent 1991-01-01 44.4949 1992-01-01 44.4949 1993-01-01 96.1472 1994-01-01 96.6037 1995-01-01 99.6597 1996-01-01 99.0232 1997-01-01 99.0399 1998-01-01 99.5693 1999-01-01 99.7587 2000-01-01 99.7759 2001-01-01 99.8140 2002-01-01 99.8463 2003-01-01 99.8796 2004-01-01 99.9222 2005-01-01 99.9408 2006-01-01 99.9676 2007-01-01 99.9776 2008-01-01 99.9800 2009-01-01 99.9766 2010-01-01 99.9690 2011-01-01 99.9639 2012-01-01 99.9595 2013-01-01 99.9562 2014-01-01 99.9569 2015-01-01 99.7954 2016-01-01 99.6050