Year Percent 1990-01-01 0.54687500000000000 1991-01-01 0.60767600000000000 1992-01-01 0.51679900000000000 1993-01-01 0.60643100000000000 1994-01-01 0.71383400000000000 1995-01-01 0.69721199999999990 1996-01-01 0.67501000000000000 1997-01-01 0.65774300000000010 1998-01-01 0.56693100000000010 1999-01-01 0.52781000000000000 2000-01-01 0.47143199999999996 2001-01-01 0.41989499999999996 2002-01-01 0.44190000000000000 2003-01-01 0.50878600000000000 2004-01-01 0.53306600000000000 2005-01-01 0.56979499999999990 2006-01-01 0.58676100000000000 2007-01-01 0.64871600000000000 2008-01-01 0.66376700000000000 2009-01-01 0.64872200000000000 2010-01-01 0.65241100000000000 2011-01-01 0.67374100000000000 2012-01-01 0.67086400000000000 2013-01-01 0.63747300000000000 2014-01-01 0.49960100000000000 2015-01-01 0.49232400000000000