Year	current US$
1979	56800000
1980	3000000
1981	8100000
1982	4500000
1983	6000000
1984	12200000
1985	17100000
1986	700000
1987	2000000
1988	300000
1989	700000
2008	1264403975.750103
2009	1663215827.6112998
2010	2097166100.7041276
2011	2571297262.5311995
2012	1806943054.578208
2013	835605678.9732744
2014	1281911084.5875154
2015	779433349.0043366
2016	441230927.7810876
2017	314378125.8567308
2018	621045042.723522
2019	504479752.81289995
2020	597448826.1155579