Year Percent Change from Year Ago 1996-01-01 1.593089230035280 1997-01-01 3.710461879046040 1998-01-01 1.975471551657210 1999-01-01 3.563590231525570 2000-01-01 3.633596295661110 2001-01-01 0.811167815697937 2002-01-01 1.780762488787790 2003-01-01 0.774434726010236 2004-01-01 3.634934697493620 2005-01-01 2.094151322701740 2006-01-01 2.505787052668250 2007-01-01 3.449275362318840 2008-01-01 0.783259889452098 2009-01-01 -2.253421455018760 2010-01-01 2.744415628741120 2011-01-01 1.798104000624130 2012-01-01 0.234853204386556 2013-01-01 0.200513986652113 2014-01-01 1.254827442766050 2015-01-01 1.716706898186300 2016-01-01 1.488895421228340 2017-01-01 1.692644250354990