Year Index 2003-01-01 31.8 2004-01-01 33.3 2005-01-01 32.4 2006-01-01 33.5 2007-01-01 34.1 2008-01-01 34.2 2009-01-01 34.9 2010-01-01 35.2 2011-01-01 35.7 2012-01-01 35.4 2013-01-01 36.2 2014-01-01 36.1 2015-01-01 36.2