Year Percent 1999-01-01 8.71609924985574 2000-01-01 10.19590858577770 2001-01-01 10.84933281451500 2002-01-01 10.13320950969400 2003-01-01 9.45956928450432 2004-01-01 9.65658995972790 2005-01-01 8.63590117469566 2006-01-01 6.91062349478191 2007-01-01 5.55204609210628 2008-01-01 4.74716805622420 2009-01-01 6.48494646534158 2010-01-01 8.07009415455371 2011-01-01 7.75464726497029 2012-01-01 7.74184968462649 2013-01-01 7.98273899848255