Year	US Dollars
1970	-657873400
1971	-799136000
1972	-940170199.37041
1973	-1153937032.56936
1974	-1318322926.82927
1975	-1505098536.58537
1976	-1594581973.20341
1977	-1641618313.25301
1978	-2058740779.22078
1979	-2268138219.17808
1980	-2295740833.33333
1981	-2340543975.90361
1982	-2412947058.82353
1983	-2541022933.64377
1984	-2837376778.59989
1985	-2582425264.7669
1986	-2918851691.86465
1987	-2777825257.53529
1988	-3043123878.62797
1989	-3675379469.43483
1990	-3046844015.95745
1991	-1734684045.31186
1992	-289398378.37838
1993	-565312297.2973
1994	-368823783.78378
1995	-762386441.97625
1996	-499900000
1997	-737400000
1998	-1029300000
1999	-792500000
2000	-860700000
2001	-915900000
2002	-562700000
2003	-245300000
2004	279700000
2005	1140300000
2006	125700000
2007	1585300000
2008	-2299700000
2009	1245000000
2010	3119000000
2011	2240000000
2012	3771000000
2013	2991000000
2014	3947000000
2015	2349800000