Year	US Dollars
1960	20500000
1961	10000000
1962	26666666.66667
1963	79000000
1964	46000000
1965	-478666666.66667
1966	-387333333.33333
1967	-553666666.66667
1968	-833000000
1969	-1158000000
1970	-1268000000
1971	-982000000
1972	-901250000
1973	-2384250000
1974	-3090500000
1975	-3398166666.66667
1976	-2387500000
1977	-1772700000
1978	-2376411764.70588
1979	-2767400000
1980	-2460745098.03922
1981	-3029885964.91228
1982	-3093584362.13992
1983	-3161960854.09253
1984	-2382604365.62074
1985	-1585975909.74637
1986	-1526399045.57064
1987	-3352179167.18926
1988	-2639358433.92332
1989	-1838454550.19829
1990	-2910586499.35522
1991	-5319449387.91628
1992	-4503891505.02216
1993	-6000599166.10721
1994	-6603373053.0371
1995	-7812240560.55524
1996	-7878246702.38431
1997	-5379486287.47029
1998	-3021236283.2557
1999	-2977993574.4136
2000	-125573296.05376
2001	-3126946762.72678
2002	-3530330533.15885
2003	-960892382.68813
2004	102409638.55422
2005	-162221182.34285
2006	221284617.80152
2007	-1648450621.94202
2008	-1394091415.83055
2009	5458891742.74598
2010	4885798341.80262
2011	1276655208.07132
2012	-3680593.37638
2013	5305317824.30486
2014	4348855082.59035
2015	9009463770.85032
2016	6636489406.94515