Year	current US$
1980	5098.297041478557
1981	5238.593102914115
1982	5835.357656778492
1983	6314.141662852028
1984	7327.482170429373
1985	8219.247726182894
1986	8557.667544057033
1987	9321.823505145647
1988	9569.408564570938
1989	10419.917294741745
1990	10373.14882853439
1991	10020.062480638271
1992	10131.2166528718
1993	9660.928860080163
1994	9899.987807837631
1995	12253.373441296426
1996	13886.789645155493
1997	18794.08617919667
1998	19849.668969661827
1999	22134.375075890148
2000	22788.578939888343
2001	23003.520429224638
2002	24323.989396698642
2003	24017.98656652436
2004	24209.36286386792
2005	25908.065411163992
2006	26203.111942543215
2007	27043.00905881792
2008	26739.15833861153
2009	24748.42501840693
2010	24433.75747563329
2011	24095.782815362956
2012	25479.101358784512
2013	24588.78796757692
2014	25392.941579041377
2015	26400.91532746367
2016	26210.583701003343
2017	27762.097913863217
2018	27555.399115373246
2019	28943.05051136972
2020	21338.490601194473
2021	24192.527809474657