Year	current US$
1977	225891249.4578258
1978	230134072.3236539
1979	273035687.19816536
1980	388507185.3439614
1981	514526901.26228577
1982	421905379.4810105
1983	408518019.62354577
1984	337233424.7897133
1985	445151474.0058018
1986	296291742.9660576
1987	325597638.2758583
1988	384459116.44613266
1989	428584956.40247345
1990	459519084.108246
1991	584045851.2230502
1992	620903197.7155534
1993	516245989.4629646
1994	650043087.3182305
2009	878479525.456571
2010	1325532364.89701
2011	1770153539.42193
2012	1730916778.7823498
2013	1857576004.0996847
2014	1900510903.7799282
2015	1467066601.8806565
2016	1227725826.88887
2017	1109446450.15752
2018	1008477563.0786301
2019	880757259.75136
2020	741987332.669433