Year Dollars 1992-01-01 4825915009 1997-01-01 12042729351 2002-01-01 11040053519 2003-01-01 12250239807 2004-01-01 12053053704 2005-01-01 13558648322 2006-01-01 16206193727 2007-01-01 17807774683 2008-01-01 18155774046 2009-01-01 12866140726 2010-01-01 14482089491 2011-01-01 16478508421 2012-01-01 16833024388 2013-01-01 17917543547 2014-01-01 19603668207 2015-01-01 20909720960 2016-01-01 19622976603