Year Percent 2002-01-01 2.23 2003-01-01 2.31 2004-01-01 2.21 2005-01-01 2.25 2006-01-01 2.05 2007-01-01 2.20 2008-01-01 2.43 2009-01-01 2.74 2010-01-01 2.92 2011-01-01 2.72 2012-01-01 2.79 2013-01-01 2.97 2014-01-01 3.09 2015-01-01 3.23 2016-01-01 3.05