Year	current US$
1990	31702812.0263986
1991	30249404.0634934
1992	31964423.058466
1993	28342435.1361832
1994	17706004.1997203
1995	21045841.9465828
1996	19336316.9837106
1997	16878180.074861
1998	16672949.6545473
1999	16849717.0285502
2000	15605343.1820765
2001	15358548.6138626
2002	16048554.0625237
2003	19384878.4721478
2004	20207547.9601674
2005	21180396.0978056
2006	21309825.3866816
2007	22525540.6249096
2008	25081636.5549472
2009	23204807.9958227
2010	22289218.6840933
2011	25116319.1861786
2012	25128141.7755067
2013	24986319.6368921
2014	26154525.8638545
2015	21846758.4962598
2016	21013993.7203638
2017	21050462.6183216
2018	22282350.280056
2019	22099365.3379867
2020	22981538.4145567
2021	24422921.8877621