Year Percent 1996-01-01 0.009973000000000001 1997-01-01 0.024462000000000000 1998-01-01 0.032681000000000000 1999-01-01 0.037297000000000004 2000-01-01 0.037357999999999995 2001-01-01 0.039279000000000000 2002-01-01 0.044839000000000000 2003-01-01 0.040789000000000000 2004-01-01 0.038807999999999995 2005-01-01 0.037248000000000000 2006-01-01 0.036137000000000000 2007-01-01 0.046937000000000000 2008-01-01 0.064775000000000000 2009-01-01 0.073226000000000000 2010-01-01 0.081703000000000000 2011-01-01 0.108127000000000000 2012-01-01 0.130424000000000000 2013-01-01 0.153805000000000000 2014-01-01 0.168936999999999980 2015-01-01 0.196509000000000000 2016-01-01 0.224636999999999980