Year	current US$
1970	921372.776492012
1971	3213403.07169317
1972	4420850.23046998
1973	5325874.61863375
1974	24568733.0249003
1975	22611694.7618011
1976	21233716.741534
1977	17433504.5758361
1978	14433688.8465958
1979	28142518.0090753
1980	38874178.3772909
1981	27997080.2901941
1982	16848484.5366365
1983	22371006.8227966
1984	22474890.4085623
1985	16022395.624436
1986	5317327.55611093
1987	9203077.68330062
1988	9615206.81616854
1989	20190180.6050702
1990	37456556.5885942
1991	21105707.2484657
1992	6797112.07080793
1993	5212502.25253845
1994	3378607.60874804
1995	2990635.88848986
1996	2829218.60107
1997	1810158.26206631
1998	317510.724718334
1999	525514.015521394
2000	975711.430101895
2001	931791.157954279
2002	456692.791788635
2003	773161.24611618
2004	645519.956854295
2005	910502.645556612
2006	1240119.25803236
2007	1130141.61627023
2008	1876053.71085476
2009	1054488.42758923
2010	1266342.52431346
2011	1394702.76318462
2012	2194823.490896
2013	2018712.96601789
2014	2476803.32213965
2015	1072668.29753299
2016	2830457.57565371
2017	6291277.07052154
2018	12643738.9018978
2019	13286737.8843902
2020	8915942.2264217
2021	25401006.8231829