Year Percent 1996-01-01 30.476200000000000 1997-01-01 53.692500000000000 1998-01-01 39.664600000000000 1999-01-01 38.367600000000000 2000-01-01 43.443000000000005 2001-01-01 47.252700000000000 2002-01-01 47.252700000000000 2003-01-01 47.252700000000000 2004-01-01 56.185600000000000 2005-01-01 57.014600000000000 2006-01-01 46.702900000000000 2007-01-01 52.727500000000000 2008-01-01 45.668200000000000 2009-01-01 39.185900000000000 2010-01-01 43.905900000000000 2011-01-01 47.603700000000000 2012-01-01 50.055100000000000 2013-01-01 52.286300000000000 2014-01-01 47.394700000000000