Year	current US$
1987	13476190476.190477
1988	15000000000
1989	17973684210.526314
1990	19457142857.142857
1991	18897435897.435898
1992	15410866372.980911
1993	14141060834.145046
1994	7657733560.917262
1995	6638932150.371311
1996	5449122122.320739
1997	6276663060.562144
1998	5054414253.766623
1999	3750203973.3277936
2000	4516902125.331764
2001	5493940916.959848
2002	5539905662.5912285
2003	5460848262.639779
2004	7015792442.188381
2005	7920223684.023096
2006	8099405940.59406
2007	9344950495.049505
2008	12293769333.012608
2009	8393657492.260539
2010	10452592412.532879
2011	13801083217.038885
2012	14171516584.409842
2013	16558738896.534468
2014	13556795059.065798
2015	10977766778.922739
2016	10946630027.222845
2017	11408184939.085836
2018	13271745231.667133
2019	13795893759.666302
2020	14581346565.804783
2021	21746056219.13709
2022	13887323171.986956
2023	13237615247.337387