Year	current US$
1975	1211392.90555033
1976	1191334.74527102
1977	1518787.60170814
1978	1951316.59971079
1979	2159095.19995828
1980	2809264.57863111
1981	4171211.31634371
1982	3587824.86845479
1983	3597780.47670882
1984	3967068.3801809
1985	4071600.8149984
1986	4565275.07929157
1987	5433253.87946435
1988	7105003.34664084
1989	7295993.18335717
1990	7954560.04579431
1991	8621399.9147846
1992	9055261.40464126
1993	8881600.10695263
1994	14497721.3167405
1995	17405972.1457235
1996	17880978.6040855
1997	16191824.8605438
1998	15892522.2208626
1999	15879427.2857885
2000	17321842.2412586
2001	15251953.9191326
2002	14686368.2611773
2003	16179756.7752221
2004	19319068.17544
2005	22132647.862899
2006	23164740.9879693
2007	23922235.4426829
2008	27127719.6767545
2009	25129026.6233243
2010	32217213.1508819
2011	36922278.6120536
2012	42093042.0191614
2013	39442215.7717865
2014	38114640.2860068
2015	39343844.7814398
2016	37480989.718292
2017	41834458.8475551
2018	43272344.0267333
2019	44971787.7368769
2020	44795958.0554437
2021	43299751.8854468