Year Percent 2000-01-01 5.55 2001-01-01 5.22 2002-01-01 5.13 2003-01-01 5.35 2004-01-01 5.47 2005-01-01 5.99 2006-01-01 6.17 2007-01-01 6.42 2008-01-01 6.07 2009-01-01 6.84 2010-01-01 6.97 2011-01-01 7.09 2012-01-01 7.82 2013-01-01 8.49 2014-01-01 8.56 2015-01-01 9.05