Year Percent 1995-01-01 14.042300000000000 1996-01-01 13.986600000000000 1997-01-01 13.750900000000000 1998-01-01 12.901600000000000 1999-01-01 14.704300000000000 2000-01-01 15.781400000000000 2001-01-01 16.859900000000000 2002-01-01 18.654000000000000 2003-01-01 17.122700000000000 2004-01-01 17.915800000000000 2005-01-01 19.379400000000000 2006-01-01 20.477999999999998 2007-01-01 22.752500000000000 2008-01-01 16.423100000000000 2009-01-01 12.596900000000000 2010-01-01 12.294900000000000 2011-01-01 12.424600000000000 2012-01-01 12.812000000000001 2013-01-01 15.097900000000000 2014-01-01 16.349800000000000 2015-01-01 16.472300000000000 2016-01-01 15.998000000000000 2017-01-01 17.375800000000000