Year Dollars 1992-01-01 5088955240 1997-01-01 10782236081 2002-01-01 13834292394 2003-01-01 15351369167 2004-01-01 13656940043 2005-01-01 14620438555 2006-01-01 16222468165 2007-01-01 17987453269 2008-01-01 17750273007 2009-01-01 12394608619 2010-01-01 15101901838 2011-01-01 16450617105 2012-01-01 17143006272 2013-01-01 17357948246 2014-01-01 18028530675 2015-01-01 17906994234 2016-01-01 16722716573