Year Percent 2008-01-01 56.65940000000000 2009-01-01 62.25710000000000 2010-01-01 52.78780000000000 2011-01-01 67.16790000000000 2012-01-01 65.08640000000000 2013-01-01 68.09720000000000 2014-01-01 67.48899999999999 2015-01-01 59.25870000000000 2016-01-01 58.42370000000000