Year Percent Change from Year Ago 1996-01-01 3.516281143075430 1997-01-01 5.114380072409960 1998-01-01 3.285631581507450 1999-01-01 5.274354012549230 2000-01-01 4.155433810962300 2001-01-01 2.949365438280240 2002-01-01 3.836305370176240 2003-01-01 2.842083168134630 2004-01-01 4.351795440063820 2005-01-01 4.003007433012070 2006-01-01 5.655999111302960 2007-01-01 6.941645694005560 2008-01-01 3.300130187668020 2009-01-01 -7.797276561491300 2010-01-01 1.237755965801490 2011-01-01 0.649366963849754 2012-01-01 -2.669582162170640 2013-01-01 -1.132054886740820 2014-01-01 2.950565120091450 2015-01-01 2.304895775012650 2016-01-01 3.068087141476620 2017-01-01 4.880537576023690