Year	current US$
1968	18640000.2557784
1969	18080000.1639873
1970	22330000.3837794
1971	26819999.800995
1972	30320000.1604855
1973	29439999.3550032
1974	30190000.1484901
1975	44340000.0222027
1976	31490000.2256036
1977	28649999.903515
1978	51989999.4879961
1979	55069999.177008905
1980	96269999.26753339
1981	100400000.989437
1982	87219999.3301183
1983	82370000.2655387
1984	73390001.1368096
1985	84780000.7350743
1986	96520000.7166713
1987	118219999.294728
1988	130550000.498071
1989	130629999.54819699
1990	145370000.70698598
1991	138119999.51116702
1992	116609998.99730101
1993	105489999.86424999
1994	97339999.800548
1995	105599999.746308
1996	89510000.8156151
1997	110280001.69247401
1998	85179999.6197224
1999	74250000.1378357
2000	62149999.052286096
2001	50769999.8132885
2002	38619999.665767
2003	36370000.09045
2004	52050000.436604
2005	60979999.8998642
2006	63980000.6840378
2007	63429999.6420741
2008	61679999.8488277
2009	62180000.7373095
2010	63709999.604150705
2011	52529999.580234304
2012	55306847.9431367
2013	49121058.135235205
2014	48911337.6876339
2015	42928491.7689547
2016	34215515.431948
2017	29839414.596182898
2018	20336227.8463319
2019	22869530.9292525
2020	21020766.299217902
2021	22181742.005515803
2022	24028249.725699432