Year	current US$
1970	28685000
1971	35243800
1972	41083001.04931795
1973	48972014.47527141
1974	53833292.68292683
1975	70650609.75609757
1976	74306820.9500609
1977	68409036.14457832
1978	74395844.15584415
1979	74468356.16438356
1980	178032222.22222224
1981	105095662.65060242
1982	40851058.823529415
1983	20809545.983701978
1984	47338759.24871941
1985	793763511.3003602
1986	-324857811.37509
1987	-362585781.50833017
1988	-113270844.32717678
1989	192664359.8615917
1990	82094946.80851063
1991	-2097903644.0562303
1992	-2001783783.783784
1993	-1629996351.3513513
1994	-839744459.4594594
1995	-225104174.6457296
1996	1058000000
1997	814000000
1998	276000000
1999	72000000
2000	192000000
2001	215000000
2002	15000000
2003	108000000
2004	124600000
2005	773200000
2006	648148148.1481481
2007	268240740.74074072
2008	2262037037.037037
2009	1300000000
2010	850000000
2011	524000000
2012	595000000
2013	887000000
2014	248000000
2015	650000000
2016	684000000
2017	410000000
2018	587000000
2019	293000000
2020	65000000