Year	current US$
1981	48746956666.66667
1982	59579616666.66667
1983	46143832258.064514
1984	50014483870.96774
1985	52242225806.451614
1986	53286422580.64516
1987	59393196774.19355
1988	66579645161.29033
1989	68420922580.64516
1990	181367051612.90323
1991	399536945.2449568
1992	522485266.95526695
1993	984548910.7767334
1994	3781588740.733609
1995	12295913879.099506
1996	10150429630.6996
1997	9023528464.903831
1998	11723849756.215012
1999	25051846326.716248
2000	26371347665.279705
2001	28503970123.376793
2002	20351090847.79503
2003	19347897185.874542
2004	29007735311.441166
2005	39875956956.356995
2006	46749400167.61382
2007	59178882413.505135
2008	83040388642.50473
2009	94469231096.41382
2010	109746371623.93163
2011	132853107264.95726
2012	152330716848.4688
2013	179161660979.4168
2014	178814995025.729
2015	157943090964.5754
2016	155237380524.97882
2017	160282392060.81082
2018	175079858972.73303
2019	198645212013.53638
2020	175743952418.35764
2021	166681768868.27588