Year	US Dollars, Monthly Level
1960-01-01	-295891081.01953800
1961-01-01	-284507988.38575600
1962-01-01	-289442858.21488005
1963-01-01	-352717024.89219100
1964-01-01	-416470996.34549900
1965-01-01	-502451072.61457000
1966-01-01	-652187424.11450210
1967-01-01	-506318047.02109295
1968-01-01	-511243401.88824800
1969-01-01	-417521974.02953500
1970-01-01	-692711856.00382010
1971-01-01	-1024069268.64182010
1972-01-01	-1339991306.73420000
1973-01-01	-1834992558.59987020
1974-01-01	-1866956673.56773020
1975-01-01	-1871036101.30610010
1976-01-01	-2995259861.93274970
1977-01-01	-4436724921.23659000
1978-01-01	-3848498696.08458000
1979-01-01	-4705821609.13247000
1980-01-01	-6900181648.72094000
1981-01-01	-5207114971.99520000
1982-01-01	-3876960213.89823000
1983-01-01	-4004813595.33455000
1984-01-01	-3853951038.27442000
1985-01-01	-3701270164.40426970
1986-01-01	-4300339208.39079000
1987-01-01	-5497640107.65393000
1988-01-01	-5538328988.80265000
1989-01-01	-6528696565.19168950
1990-01-01	-7972117737.78854100
1991-01-01	-9632901660.78570000
1992-01-01	-9628250811.57703000
1993-01-01	-8386896168.25326100
1994-01-01	-10228151121.45900000
1995-01-01	-8793249329.02698000
1996-01-01	-10567102054.08920000
1997-01-01	-6037229241.87726000
1998-01-01	-5408038841.42839050
1999-01-01	-5350307379.51784000
2000-01-01	-4720411529.40397900
2001-01-01	-3906214008.88604000
2002-01-01	333438531.77475303
2003-01-01	-2298785084.58882000
2004-01-01	-1592570962.33858000
2005-01-01	-2174071327.63390000
2006-01-01	-381073251.01766600
2007-01-01	576055297.39808000
2008-01-01	-3083412943.86312000
2009-01-01	-6105025582.91948000
2010-01-01	-6539093284.84397000
2011-01-01	-13965761992.84330000
2012-01-01	-11717258651.90890000
2013-01-01	-8154147211.61840000
2014-01-01	-3775399158.81991000
2015-01-01	-3230788938.79876000
2016-01-01	-5465222779.52485900
2017-01-01	-7345448432.60568000