Year Percent 1998-01-01 6.83551398818118 1999-01-01 6.02390602430583 2000-01-01 5.22549604257516 2001-01-01 4.60115069966816 2002-01-01 4.57987693146888 2003-01-01 4.52070900530339 2004-01-01 4.39663254409710 2005-01-01 4.20519745698840 2006-01-01 3.89925924453019 2007-01-01 3.48202405580094 2008-01-01 3.25467005509005 2009-01-01 4.15539275373252 2010-01-01 4.19835085722873 2011-01-01 3.89071722722771 2012-01-01 3.83629096621293 2013-01-01 4.04740479945380