Year	US Dollars, Monthly Level
1960-01-01	-356953761.100604000
1961-01-01	-659109984.206000900
1962-01-01	-790791706.836200000
1963-01-01	-822518824.896444000
1964-01-01	-946303241.107830000
1965-01-01	-715456622.917809000
1966-01-01	-656457899.850394000
1967-01-01	-618001179.577866100
1968-01-01	-482215002.704519000
1969-01-01	-645362816.543546000
1970-01-01	-1331827120.641320000
1971-01-01	-1461944518.472690000
1972-01-01	-1649040055.299440000
1973-01-01	-2101405955.557060000
1974-01-01	-2536607108.232370000
1975-01-01	-333655556.463304040
1976-01-01	54803764.353613995
1977-01-01	-386834052.777785000
1978-01-01	-275171186.899651000
1979-01-01	-2822965044.553889800
1980-01-01	-6147533348.352250000
1981-01-01	-3698077331.136350000
1982-01-01	-2653069125.236490000
1983-01-01	-3546162032.365990000
1984-01-01	-3568464580.342890000
1985-01-01	-3282235967.089490000
1986-01-01	-3632017148.674569600
1987-01-01	-5037932586.876470000
1988-01-01	-5692274172.533780000
1989-01-01	-6763050469.631290000
1990-01-01	-6426128085.246119500
1991-01-01	-4625618455.260210000
1992-01-01	-307712517.517021000
1993-01-01	2041943284.700830000
1994-01-01	2161886010.683860000
1995-01-01	1067251024.300030000
1996-01-01	1873179316.950060000
1997-01-01	1418107644.933810000
1998-01-01	1588471959.602230000
1999-01-01	756094069.806096900
2000-01-01	-1278428133.823990000
2001-01-01	1096978333.082360000
2002-01-01	4993695854.480620000
2003-01-01	5163490620.227221000
2004-01-01	7713807917.200391000
2005-01-01	6398437704.252260000
2006-01-01	9676737869.407790000
2007-01-01	11732690674.359200000
2008-01-01	18058512213.790800000
2009-01-01	19136898647.248800000
2010-01-01	18699376281.582200000
2011-01-01	26641094812.867302000
2012-01-01	25196937738.622800000
2013-01-01	25399581546.012300000
2014-01-01	32362087348.979300000
2015-01-01	38012054671.645000000
2016-01-01	37722624693.899000000
2017-01-01	35525129036.243300000