Year Percent 2005-01-01 7.6925000000000000 2006-01-01 7.5561300000000005 2007-01-01 7.6231899999999990 2008-01-01 5.4960400000000000 2009-01-01 6.0393200000000000 2010-01-01 3.4789999999999996 2011-01-01 4.5265400000000000 2012-01-01 4.2095400000000005 2013-01-01 3.8448000000000000 2014-01-01 3.6237300000000000 2015-01-01 3.3617800000000004 2016-01-01 3.1500600000000000