Year Dollars 1997-01-01 6993882 2002-01-01 13868602 2003-01-01 17716098 2004-01-01 23954139 2005-01-01 15629644 2006-01-01 21534388 2007-01-01 38325861 2008-01-01 34312185 2009-01-01 37262088 2010-01-01 44192995 2011-01-01 46705694 2012-01-01 46370799 2013-01-01 49300975 2014-01-01 45962009 2015-01-01 45417075 2016-01-01 43861469