Year Dollars 1997-01-01 3314651 2002-01-01 15615944 2005-01-01 24767356 2006-01-01 37952478 2007-01-01 32736997 2008-01-01 37138034 2009-01-01 25588569 2010-01-01 24391758 2011-01-01 18754697 2012-01-01 18669559 2013-01-01 31309797 2014-01-01 20548256 2015-01-01 15395328 2016-01-01 19670685