Year Percent 2005-01-01 4.57885 2006-01-01 4.36618 2007-01-01 0.00000 2008-01-01 3.30134 2009-01-01 40.58840 2010-01-01 97.40860 2011-01-01 83.94060 2012-01-01 22.57010 2013-01-01 13.04720