Year Percent 2005-01-01 1.80096191854868 2006-01-01 1.82857431340747 2007-01-01 1.86309488454335 2008-01-01 2.07780345274674 2009-01-01 2.94938850903179 2010-01-01 2.97090579159489 2011-01-01 2.89080366874049 2012-01-01 2.75461651938073 2013-01-01 2.74192322184098 2014-01-01 2.67673795016440 2015-01-01 2.37670884951406 2016-01-01 2.15977429032839 2017-01-01 1.86798410483183