Year Percent 1992-01-01 90.77760000000000 1993-01-01 86.95720000000000 1994-01-01 87.61670000000000 1995-01-01 88.77799999999999 1996-01-01 89.73740000000000 1997-01-01 95.11270000000000 1998-01-01 99.99990000000000 1999-01-01 99.99990000000000 2000-01-01 99.99990000000000 2001-01-01 99.99990000000000 2002-01-01 99.94770000000000 2003-01-01 99.89820000000000 2004-01-01 99.92000000000000 2005-01-01 99.94510000000000 2006-01-01 99.94900000000000 2007-01-01 99.94880000000000 2008-01-01 99.94280000000000 2009-01-01 99.93890000000000 2010-01-01 99.94430000000000 2011-01-01 99.94750000000000 2012-01-01 99.94410000000000 2013-01-01 99.94020000000000 2014-01-01 99.94520000000000 2015-01-01 99.95220000000000 2016-01-01 99.87000000000000