Year Percent 1990-01-01 0.66863500000000010 1991-01-01 0.56055500000000000 1992-01-01 0.48483000000000004 1993-01-01 0.34944300000000000 1994-01-01 0.39045400000000000 1995-01-01 0.45471900000000000 1996-01-01 0.58681600000000000 1997-01-01 0.73161700000000000 1998-01-01 0.80061300000000000 1999-01-01 0.63239600000000000 2000-01-01 0.60746400000000000 2001-01-01 0.64077500000000000 2002-01-01 0.79618700000000000 2003-01-01 0.71917600000000000 2004-01-01 0.61692000000000000 2005-01-01 0.57424800000000000 2006-01-01 0.56767700000000010 2007-01-01 0.53032800000000000 2008-01-01 0.47712100000000000 2009-01-01 0.38659099999999996 2010-01-01 0.44910200000000006 2011-01-01 0.45010700000000000 2012-01-01 0.48274700000000004 2013-01-01 0.50314100000000000 2014-01-01 0.43136700000000000 2015-01-01 0.40234200000000003 2016-01-01 0.39086000000000000