Year Percent Change From Preceding Period 2004-01-01 6.98785780342402 2005-01-01 8.61022528546410 2006-01-01 11.55332449327570 2007-01-01 7.07721306186182 2008-01-01 12.62324225657260 2009-01-01 8.10797490723941 2010-01-01 6.94957310044372 2011-01-01 8.47320068490520 2012-01-01 7.53714538751766 2013-01-01 5.88218740520660 2014-01-01 4.41462530312324 2015-01-01 3.05416132792560 2016-01-01 2.80969374444781 2017-01-01 3.29620106136526 2018-01-01 3.79151350244106 2019-01-01 3.88274688512596