Year Dollars 1992-01-01 22874435 1997-01-01 29823646 2002-01-01 27864325 2003-01-01 21037588 2004-01-01 27519582 2005-01-01 30162262 2006-01-01 36093601 2007-01-01 38871456 2008-01-01 44701867 2009-01-01 25418471 2010-01-01 29154697 2011-01-01 23423324 2012-01-01 17716213 2013-01-01 20334610 2014-01-01 20995731 2015-01-01 23229115 2016-01-01 25830357