Year Percent 2005-01-01 50.3942052731106 2006-01-01 50.3221249864334 2007-01-01 50.9457590615570 2008-01-01 51.0976406545683 2009-01-01 49.5653815880654 2010-01-01 49.0428527560770 2011-01-01 48.9962106755637 2012-01-01 48.6098432741928