Year Dollars 1992-01-01 866253 1997-01-01 1725100 2002-01-01 355121 2003-01-01 1063353 2004-01-01 1411751 2005-01-01 1360307 2006-01-01 2914081 2007-01-01 3617826 2008-01-01 7870775 2009-01-01 18818527 2010-01-01 24232681 2011-01-01 18348131 2012-01-01 22153006 2013-01-01 21995391 2014-01-01 21884160 2015-01-01 16128535 2016-01-01 20711592