Year	constant 2015 US$
1998	8272303945.785871
1999	7090560057.29039
2000	6234574796.143625
2001	6977806161.098834
2002	7711555001.936136
2003	9335305826.41066
2004	11194129477.443785
2005	12982566474.353682
2006	13309356756.172394
2007	17528960962.307095
2008	23416751840.17834
2009	22086938914.594673
2010	20079956747.660915
2011	21933459057.480247
2012	23493902646.522305
2013	25738956713.357742
2014	26436110949.905476
2015	26770611183.355007
2016	30816949007.316162
2017	29753238264.946655
2018	29904599620.58257
2019	26790959947.556522
2020	27285130801.191048
2021	26882855802.94114