Year Percent 1999-01-01 3.56731745918629 2000-01-01 3.26656793051420 2001-01-01 3.02787437403083 2002-01-01 3.07192610356145 2003-01-01 3.21501070808815 2004-01-01 3.17148772146398 2005-01-01 3.30343829015787 2006-01-01 3.03250176716013 2007-01-01 2.47559008891114 2008-01-01 2.23995054275835 2009-01-01 2.99225292994516 2010-01-01 3.68011110398344 2011-01-01 4.05948684368276 2012-01-01 4.35813816260778 2013-01-01 4.94550184981155 2014-01-01 4.76024899073318