Year Percent Change From Preceding Period 2004-01-01 65.09410715146360 2005-01-01 54.29021871522090 2006-01-01 97.77051475894470 2007-01-01 79.94325548627520 2008-01-01 62.64299910437940 2009-01-01 60.50249453117430 2010-01-01 19.17783273404270 2011-01-01 28.80007843657790 2012-01-01 24.21081009581250 2013-01-01 15.02550419124220 2014-01-01 1.14642668389198 2015-01-01 17.61471838209230 2016-01-01 -1.75361131184904 2017-01-01 -1.26125075778511