Year Percent 1995-01-01 8.61523418550000 1996-01-01 7.82529326450000 1997-01-01 8.80914594725000 1998-01-01 9.22969245550000 1999-01-01 9.41321224700000 2000-01-01 9.19558621625000 2001-01-01 9.91099914775000 2002-01-01 10.61265664700000 2003-01-01 11.33759996250000 2004-01-01 11.39714240500000 2005-01-01 9.53951316775000 2006-01-01 9.00651105250000 2007-01-01 7.94582327300000 2008-01-01 6.50929171600000 2009-01-01 7.55505253850000 2010-01-01 6.50542061000000 2011-01-01 5.63284943300000 2012-01-01 6.96666666666667 2013-01-01 6.27500000000000 2014-01-01 5.91666666666667 2015-01-01 5.40833333333333 2016-01-01 4.95000000000000 2017-01-01 4.33333333333333