Year Percent Change From Preceding Period 2004-01-01 6.73837393229987 2005-01-01 6.13515115589798 2006-01-01 5.32101483845423 2007-01-01 6.25609308646734 2008-01-01 6.22974912331943 2009-01-01 2.85457339168750 2010-01-01 7.10797657621968 2011-01-01 6.87400000000011 2012-01-01 7.08757117287811 2013-01-01 8.48195663552300 2014-01-01 9.47022397661296 2015-01-01 6.91634957376361 2016-01-01 2.40026540906264 2017-01-01 3.41385444394519 2018-01-01 3.82424362305146 2019-01-01 4.11357482747138