Year	current US$
1977	40218498.23
1978	42233234.41
1979	94783645.63
1980	134977966.3
1981	122062927.2
1982	110731514
1983	83272193.91
1984	62716938.02
1985	15254607.2
1986	20079193.12
1987	16780281.07
1988	15489000.32
1989	15853200.91
1990	9116352.21617445
1991	7196323.32027429
1992	9136897.74793044
1993	6691332.06687581
1994	6239535.57883958
2009	8559307.80130909
2010	9021510.42257978
2011	9445521.41244103
2012	9889460.91882576
2013	10354265.5820106
2014	10840916.0643651
2015	11350439.1193902
2016	13844871.1232992
2017	18574999.616
2018	29278892.4471958
2019	13480565.662
2020	21707094.032