Year Percent 1992-01-01 76.52650000000000 1993-01-01 74.48600000000000 1994-01-01 74.48600000000000 1995-01-01 90.58240000000000 1996-01-01 88.72830000000000 1997-01-01 87.78520000000000 1998-01-01 87.51740000000000 1999-01-01 89.46600000000001 2000-01-01 92.48150000000000 2001-01-01 93.76560000000000 2002-01-01 94.20520000000000 2003-01-01 95.01360000000000 2004-01-01 95.63920000000000 2005-01-01 96.59260000000000 2006-01-01 97.32900000000000 2007-01-01 98.22510000000000 2008-01-01 99.03930000000000 2009-01-01 97.58300000000000 2010-01-01 96.73080000000000 2011-01-01 97.62360000000000 2012-01-01 98.50940000000000 2013-01-01 99.04520000000000 2014-01-01 99.54420000000000 2015-01-01 99.08930000000000 2016-01-01 99.04799999999999