Year	US Dollars, Monthly Level
1980-01-01	19860518041.386200
1981-01-01	24925737241.375698
1982-01-01	15069205480.379700
1983-01-01	9006439823.138620
1984-01-01	12136409689.698301
1985-01-01	14531040141.341000
1986-01-01	12424850061.030100
1987-01-01	13281289118.644600
1988-01-01	20174323488.916103
1989-01-01	25488798723.614800
1990-01-01	31201023755.656197
1991-01-01	49900891133.673400
1992-01-01	61748460135.135090
1993-01-01	65279481139.377910
1994-01-01	79420662037.390200
1995-01-01	72521486496.915900
1996-01-01	88772408436.909700
1997-01-01	109411803575.674990
1998-01-01	125301922597.300000
1999-01-01	141409610263.141000
2000-01-01	174287024877.594000
2001-01-01	168372884414.603970
2002-01-01	168230521806.969000
2003-01-01	170429636826.899020
2004-01-01	195662092874.775000
2005-01-01	221972213743.269000
2006-01-01	256238659074.660000
2007-01-01	281597374931.071000
2008-01-01	307214879537.506040
2009-01-01	234358643787.525020
2010-01-01	300856976155.864000
2011-01-01	351407003352.161000
2012-01-01	370275100491.849000
2013-01-01	380409072527.413000
2014-01-01	399889689259.204000
2015-01-01	395320886131.496030
2016-01-01	386844731916.934000
2017-01-01	420871074496.202000