Year	current US$
1970	18161689.9346172
1971	18688866.5333333
1972	16311089.3777778
1973	23024416.2777777
1974	33405361.4411262
1975	29013333.3333334
1976	39607770.275301
1977	42248887.7688889
1978	51136157.4676116
1979	52860413.0526315
1980	59464851.9546485
1981	60375754.9313132
2009	338502672.678568
2010	444324240.243129
2011	520334664.430149
2012	569623570.938043
2013	576468821.935881
2014	612803653.538383
2015	523532102.941459
2016	472166739.725436
2017	496707377.967453
2018	482833320.042869
2019	498263992.940825
2020	527512991.719678
2021	386856048.870212