Year	current US$
1972	15964071.856287425
1973	24512769.296618633
1974	41448016.897441916
1975	30523478.440731484
1976	29888156.190271348
1977	29448063.648712333
1978	31919776.480297234
1979	36916483.818649046
1980	42393685.58168345
1981	43847784.74285091
1982	35647955.14184019
1983	32981536.28554569
1984	31830974.2970499
1985	27025026.276368033
1986	26422919.114904404
1987	28954333.487375543
1988	33468811.820849624
1989	36868662.506711625
1990	36113927.79556257
1991	41100489.50112016
1992	41590043.829242215
2006	178586838.7384382
2007	205580249.55818564
2008	222791563.00485328
2009	208493209.65941837
2010	236268837.84842393
2011	280640725.8451328
2012	288846563.62956756
2013	276718093.3790159
2014	284917560.7984041
2015	254008594.46017924
2016	275196808.83487684
2017	293544243.45357525
2018	298885544.9592502
2019	291622494.7115308
2020	273817911.5468125
2021	355081443.30889165