Year Dollars 1992-01-01 5103002396 1997-01-01 8876656931 2002-01-01 9760818525 2003-01-01 10417970922 2004-01-01 11469013079 2005-01-01 13389481416 2006-01-01 15700550668 2007-01-01 17895430872 2008-01-01 18806283447 2009-01-01 15417407754 2010-01-01 18214217111 2011-01-01 20375554886 2012-01-01 21303033722 2013-01-01 21066543439 2014-01-01 21390107634 2015-01-01 20331760470 2016-01-01 18990116342