Year Percent 1999-01-01 6.91710643611729 2000-01-01 6.27774936759842 2001-01-01 4.70994123840949 2002-01-01 5.27367769631994 2003-01-01 5.41025992639737 2004-01-01 5.24701753025487 2005-01-01 4.46356749599406 2006-01-01 4.18207913513938 2007-01-01 4.11384742297444 2008-01-01 5.69139928611935 2009-01-01 9.03609652519279 2010-01-01 10.05464878950730 2011-01-01 10.82461238939690 2012-01-01 12.54428373415130 2013-01-01 13.11265935888700 2014-01-01 12.19794773743610