Year	US Dollars, Monthly Level
1960-01-01	829672144.8991040
1961-01-01	794615355.9702590
1962-01-01	798463217.9706420
1963-01-01	910568080.0229050
1964-01-01	1056417255.6727899
1965-01-01	998921120.8044319
1966-01-01	1067890003.6683800
1967-01-01	974341439.4453430
1968-01-01	1004098861.0820100
1969-01-01	1209711902.1515000
1970-01-01	1220825866.7687600
1971-01-01	1371343418.7244600
1972-01-01	1796906955.1853000
1973-01-01	2599441758.6966700
1974-01-01	2445238709.8920603
1975-01-01	2180254001.4106000
1976-01-01	2795396117.7429600
1977-01-01	3213046266.0855800
1978-01-01	3777980702.7733900
1979-01-01	4712478820.3398400
1980-01-01	5403486907.7471100
1981-01-01	5596768910.4449400
1982-01-01	5687798594.4706400
1983-01-01	5403250152.5378400
1984-01-01	5471414201.6893410
1985-01-01	5729722601.8234500
1986-01-01	5889150716.6206800
1987-01-01	7180003381.4146390
1988-01-01	8782462720.9501100
1989-01-01	8867401513.0239600
1990-01-01	9415977185.6058800
1991-01-01	9649181801.3049200
1992-01-01	9746902830.0632600
1993-01-01	10495684614.8267000
1994-01-01	12163170001.2194000
1995-01-01	13667893539.3984000
1996-01-01	14278795242.8217000
1997-01-01	14223107437.8932000
1998-01-01	12040284532.0423980
1999-01-01	12449493548.9144000
2000-01-01	13318881587.2918000
2001-01-01	13758890074.5777990
2002-01-01	14373155404.2095000
2003-01-01	16575591570.2095000
2004-01-01	20256470798.5837000
2005-01-01	21775369398.0364000
2006-01-01	22542522764.0224000
2007-01-01	27037924044.0659980
2008-01-01	30509092593.0870000
2009-01-01	24999268216.2614000
2010-01-01	31406135598.4881970
2011-01-01	37743132082.7267000
2012-01-01	37375188092.1314000
2013-01-01	39401628729.2201000
2014-01-01	41690689743.2005000
2015-01-01	34311522808.3207000
2016-01-01	33761760222.1807000
2017-01-01	38238927237.6942000