Year	current US$
1992	208938906.752412
1993	151367237.371649
1994	140754742.268041
1995	110022000.047198
1996	129238398.228517
1997	155486122.19513
1998	162594855.036368
1999	118664830.54556
2000	116966455.708976
2001	114419368.065238
2002	111880392.319853
2003	121517418.491827
2004	145056708.274207
2005	171035768.033477
2006	197323507.019288
2007	239762894.531147
2008	280369022.57273
2009	220285910.938554
2010	229355013.826434
2011	258395129.985177
2012	287161654.357172
2013	296955147.192498
2014	306190780.404372
2015	257228409.888512
2016	254150310.626612
2017	271875996.843993
2018	297657133.09923
2019	293793594.892169
2020	265836232.331094
2021	307294414.260861