Year Percent 2004-01-01 1.7586400000000002 2005-01-01 1.7843900000000001 2006-01-01 1.5777200000000000 2007-01-01 1.6349200000000002 2008-01-01 1.6349200000000002 2009-01-01 1.0948000000000000 2010-01-01 1.2324100000000000 2011-01-01 1.1489200000000002 2012-01-01 1.1702500000000000 2013-01-01 1.2447500000000000 2014-01-01 1.1981600000000001 2015-01-01 1.1973100000000000