Year	current US$
1976	500000
1977	100000
1978	100000
1979	1900000
1980	19600000
1981	13000000
1982	6800000
1983	1460000
1984	1700000
1985	10110000
1986	5800000
1987	9300000
1988	11900000
1989	2500000
1990	1000000
1991	600000
1992	250000
2003	20000
2004	2320000
2005	20350000
2006	470000
2007	25510000
2008	4490000
2009	10700000
2010	6950000
2011	7590000
2012	2110000
2013	1360000
2014	770000
2015	1360000
2016	4880000
2017	4320000
2018	28990000
2019	31770000
2020	14410000
2021	35630000
2022	22160000