Year Percent Change From Preceding Period 2004-01-01 43.52543930096020 2005-01-01 22.96095940827720 2006-01-01 13.30469921399290 2007-01-01 12.24928418367590 2008-01-01 12.46453380890550 2009-01-01 13.72051582848210 2010-01-01 14.48011687904760 2011-01-01 13.48353762793460 2012-01-01 10.28467589829920 2013-01-01 8.78249186830954 2014-01-01 7.29825014419267 2015-01-01 9.15948925574696 2016-01-01 30.69441508067210 2017-01-01 29.84447990156770 2018-01-01 20.46141464734060 2019-01-01 15.76513605678960