Year Percent 2000-01-01 2.72 2001-01-01 4.35 2002-01-01 4.09 2003-01-01 4.48 2004-01-01 4.56 2005-01-01 5.45 2006-01-01 6.48 2007-01-01 7.23 2008-01-01 5.49 2009-01-01 7.90 2010-01-01 9.33 2011-01-01 7.92 2012-01-01 9.46 2013-01-01 9.55 2014-01-01 9.20 2015-01-01 9.19 2016-01-01 8.83