Year	current US$
1990	3173614.30958246
1991	3206082.61426224
1992	3397006.55132519
1993	2878605.50089817
1994	3023375.05958171
1995	3336904.80072655
1996	3435432.509362
1997	3465050.28474621
1998	3478524.03706492
1999	3505246.44267705
2000	3130468.86028958
2001	3374339.20555861
2002	3558239.85862476
2003	3935802.48177601
2004	4300937.52712018
2005	4654578.75986799
2006	4874537.33422405
2007	5444136.87489101
2008	6359063.96539816
2009	6755303.28554648
2010	7317451.57454304
2011	7809220.14657636
2012	6994626.77648511
2013	7152355.81233809
2014	7319542.88947112
2015	5896094.25513081
2016	5510618.74345033
2017	5633216.89535467
2018	6387840.17406683
2019	6591918.39769413
2020	6796862.83631173
2021	7108403.1916236