Year	current US$
1975	13494105.34
1976	12696014.4
1977	10833278.66
1978	15879908.56
1979	19540206.91
1980	35397003.17
1981	35704269.41
1982	47391063.69
1983	41086750.03
1984	54394626.62
1985	68969841
1986	59374298.1
1987	58762561.8
1988	91089347.84
1989	122093620.3
1990	197948154.880759
1991	53479264.659363
2009	3265400000
2010	3026910000
2011	2921350000
2012	2893154437
2013	3288960339.22959
2014	3620432108.44106
2015	3992380815.21228
2016	4155202827.76699
2017	4396768857.84787
2018	4923627285.38676
2019	8912892000.24464
2020	7878509446.59947
2021	7583522641.96769
2022	6502745251.38835