Year Percent 2005-01-01 4.27619041362807 2006-01-01 3.98894922803024 2007-01-01 3.58502350497783 2008-01-01 3.62025488107550 2009-01-01 4.55932799906341 2010-01-01 4.82056029000332 2011-01-01 4.84958843877433 2012-01-01 5.45998301229452