Year Percent 1996-01-01 100.00000000000000 1997-01-01 100.00000000000000 1998-01-01 90.23810000000000 1999-01-01 86.08210000000000 2000-01-01 85.03299999999999 2001-01-01 79.65090000000000 2002-01-01 79.56790000000000 2003-01-01 75.94110000000000 2004-01-01 92.43070000000000 2005-01-01 93.75860000000000 2006-01-01 82.39760000000000 2007-01-01 85.56720000000000 2008-01-01 86.95170000000000 2009-01-01 86.14650000000000 2010-01-01 87.26050000000000 2011-01-01 87.62470000000000 2012-01-01 89.00230000000000 2013-01-01 88.78150000000000 2014-01-01 100.00000000000000 2015-01-01 87.13550000000000