Year	current US$
1990	18693134.294513
1991	21359670.5562647
1992	23811249.6257475
1993	23185377.7521469
1994	23073683.0329801
1995	25966644.960414
1996	23223051.5274839
1997	23352621.7427908
1998	21354649.5641233
1999	20573126.9518832
2000	19206027.5844185
2001	17133509.680946
2002	15949406.7051264
2003	22857256.0429841
2004	29764867.0794789
2005	32464572.8632038
2006	33798755.7322895
2007	31410811.7283531
2008	32470928.7199207
2009	32797857.0681179
2010	41210316.03114
2011	46955993.0777602
2012	44144921.4317149
2013	43042261.2212854
2014	44835619.9848988
2015	42937639.7584965
2016	37677672.0827422
2017	42136992.3697257
2018	45338446.4081248
2019	42141439.1779923
2020	39895873.0029883
2021	41613932.4929801