Year	US Dollars, Monthly Level
1960-01-01	-329569875.71988800
1961-01-01	-179684224.25247300
1962-01-01	-191794767.53660500
1963-01-01	-195412646.94118702
1964-01-01	-193013444.36178900
1965-01-01	-414457512.74175500
1966-01-01	-326536292.57713700
1967-01-01	-180777324.32970900
1968-01-01	-210365641.81244498
1969-01-01	-212867465.20109302
1970-01-01	-232345427.11754900
1971-01-01	396320920.39205900
1972-01-01	659544072.68743500
1973-01-01	1328916577.02457000
1974-01-01	-712415581.82641790
1975-01-01	-693138309.15500000
1976-01-01	-649663708.23179200
1977-01-01	-1063460800.20733000
1978-01-01	1175459136.43065000
1979-01-01	-1123466487.05770000
1980-01-01	-2567262768.38829000
1981-01-01	-235176524.48495800
1982-01-01	-849112663.34894000
1983-01-01	1280180944.34954000
1984-01-01	2849058298.09174970
1985-01-01	1809717272.71860000
1986-01-01	4594254871.67761000
1987-01-01	3741390727.24771000
1988-01-01	3904033583.41967000
1989-01-01	2457615121.41227000
1990-01-01	2648939191.96124030
1991-01-01	5167913510.06925000
1992-01-01	6071431051.83058100
1993-01-01	7153978819.73663000
1994-01-01	9565349201.08117900
1995-01-01	14949031757.78800000
1996-01-01	17870124816.48640000
1997-01-01	17262190829.13300000
1998-01-01	16360602128.20530100
1999-01-01	16194996872.72510000
2000-01-01	14232324829.95119900
2001-01-01	13868624942.27780000
2002-01-01	15397363947.84050000
2003-01-01	18186838293.79430000
2004-01-01	22405562560.02530000
2005-01-01	19402313898.28020000
2006-01-01	20293452879.55580000
2007-01-01	15620347375.95200200
2008-01-01	14365016413.16880000
2009-01-01	11083182199.86680000
2010-01-01	9503281015.89084000
2011-01-01	10209235020.91390000
2012-01-01	7966004035.68580000
2013-01-01	6889748134.86965000
2014-01-01	2301369668.68895000
2015-01-01	1533334362.64256000
2016-01-01	-1684826533.24297000
2017-01-01	-1268695334.34183980