Year Percent 2006-01-01 0.32 2007-01-01 0.32 2008-01-01 0.33 2009-01-01 0.54 2010-01-01 0.74 2011-01-01 0.83 2012-01-01 0.90 2013-01-01 1.10 2014-01-01 0.90 2015-01-01 0.82 2016-01-01 0.92