Year Percent 2004-01-01 28.1507 2005-01-01 20.9126 2006-01-01 16.5336 2007-01-01 14.6153 2008-01-01 27.9026 2009-01-01 18.8001 2010-01-01 17.1111 2011-01-01 17.8947 2012-01-01 10.6872