Year Percent 2002-01-01 11.1265 2003-01-01 11.0117 2004-01-01 13.3335 2005-01-01 17.2745 2006-01-01 29.8893 2007-01-01 48.7504 2008-01-01 54.8474 2009-01-01 50.8555 2010-01-01 46.7904 2011-01-01 46.3996 2012-01-01 49.6578 2013-01-01 49.5765 2014-01-01 51.3418 2015-01-01 54.3949 2016-01-01 55.0043