Year Percent 2002-01-01 18.2454 2003-01-01 16.7654 2004-01-01 16.5098 2005-01-01 13.8598 2006-01-01 14.1469 2007-01-01 12.5990 2008-01-01 11.8874 2009-01-01 12.9961 2010-01-01 12.9035 2011-01-01 12.7173