Year	US Dollars
1970	-3172658846.791
1971	-4347285395.63932
1972	-4923247500.46004
1973	-4020168093.66996
1974	-2219776585.29212
1975	-8360053422.37062
1976	-11674306897.6231
1977	-12990839046.5763
1978	-14261680623.1743
1979	-31679843986.7677
1980	-44014225952.2272
1981	-31499326611.8563
1982	-20736525348.5935
1983	-23232664113.3665
1984	-20410720087.9665
1985	-15104486779.1656
1986	-4113392776.72701
1987	-4485953210.01088
1988	-5169661877.71467
1989	-8961351919.27598
1990	-3833374894.08062
1991	-9586328815.55686
1992	-11095804633.6882
1993	1334437477.81853
1994	4347354465.46945
1995	12133205950.5937
1996	20541980764.2319
1997	26245206406.4967
1998	29697677003.4456
1999	15686128276.156
2000	5246913580.24691
2001	34400894854.58611
2002	90963674007.15228
2003	91805869074.4921
2004	142110752421.15695
2005	144779256311.40402
2006	159085434700.79001
2007	228732548590.20001
2008	224198037205.215
2009	168827452070.01904
2010	177609292859.43396
2011	183699221402.7789
2012	215840140141.26492
2013	223624705187.69296
2014	269344196953.07693
2015	269842601638.55402
2016	277222634664.88007
2017	278527967429.55396