Year	US Dollars, Monthly Level
1960-01-01	-510228776.03626204
1961-01-01	-809395386.43609100
1962-01-01	-773969970.34394600
1963-01-01	-1015604742.75839010
1964-01-01	-1245802057.52344010
1965-01-01	-1069099834.23126010
1966-01-01	-1268136295.93577000
1967-01-01	-1045834195.30646000
1968-01-01	-944723634.42103700
1969-01-01	-1030095836.78443990
1970-01-01	-1637944831.32345990
1971-01-01	-1472268362.07377000
1972-01-01	-732716581.02759700
1973-01-01	-645163255.80585000
1974-01-01	-846174913.13431910
1975-01-01	-570582551.65895900
1976-01-01	-494416248.15693200
1977-01-01	-2869559629.46252970
1978-01-01	-3601098164.65641000
1979-01-01	-4366780979.28830000
1980-01-01	-4173831971.07846000
1981-01-01	1627142599.08465000
1982-01-01	1870389373.38385990
1983-01-01	3890853003.85831000
1984-01-01	3596227607.61513000
1985-01-01	3149602047.25372000
1986-01-01	4910762115.53994000
1987-01-01	1498126092.17419980
1988-01-01	3653660857.43595030
1989-01-01	3587834544.30187030
1990-01-01	5063131190.79460000
1991-01-01	6586928785.39193000
1992-01-01	5715939665.10350000
1993-01-01	14583720287.68270100
1994-01-01	16958690607.35820000
1995-01-01	18485053887.12390000
1996-01-01	18709250879.54450000
1997-01-01	17146961854.21860000
1998-01-01	18147821136.81030000
1999-01-01	12224540329.55590000
2000-01-01	15180222704.03590000
2001-01-01	22129690153.00570000
2002-01-01	24590290636.55650000
2003-01-01	31087035114.57580000
2004-01-01	37908605980.73390000
2005-01-01	42262092316.38830000
2006-01-01	46603149893.72390000
2007-01-01	57736401618.20930000
2008-01-01	57795790473.08500000
2009-01-01	54124586105.58930000
2010-01-01	61015953234.51610000
2011-01-01	72658366007.79020000
2012-01-01	69294948137.45410000
2013-01-01	81235882423.36931000
2014-01-01	82853128051.89530000
2015-01-01	57974268895.26220000
2016-01-01	70154700844.56910000
2017-01-01	75763675436.54950000