Year Percent 2000-01-01 34.54 2001-01-01 29.99 2002-01-01 25.41 2003-01-01 27.54 2004-01-01 24.42 2005-01-01 23.10 2006-01-01 19.37 2007-01-01 15.26 2008-01-01 13.21 2009-01-01 13.93 2010-01-01 13.04 2011-01-01 10.30 2012-01-01 10.07 2013-01-01 11.79 2014-01-01 14.17 2015-01-01 16.35 2016-01-01 16.89