Year Percent 2004-01-01 2.29372 2005-01-01 2.24059 2006-01-01 13.82000 2007-01-01 15.06000 2008-01-01 13.84000 2009-01-01 15.85000 2010-01-01 15.07000 2011-01-01 15.42000 2012-01-01 17.09000 2013-01-01 17.01000 2014-01-01 15.92000 2015-01-01 15.86000 2016-01-01 16.03000