Year	current US$
1981	-8343938.48670627
1982	-10711324.582715
1983	-3278962.12536036
1984	-6546917.56827093
1985	-3371330.26856124
1986	1269400.21095972
1987	-32753459.8595417
1988	-54888366.3134729
1989	548140.086468292
1990	34848590.3431749
1991	2718613.16906684
1992	2387152.75946108
1993	3467823.3995585
1994	5340428.46212701
1995	14864167.1404207
1996	22415971.25
1997	30059235.8885876
1998	33608425
1999	37885878.093658
2000	41847352.879575
2001	657349966.241516
2002	776300682.047003
2003	1065803106.11782
2004	1438477931.03967
2005	2154938523.38196
2006	4011608860.97891
2007	2934234079.5227
2008	3495829689.74069
2009	2726398152.60672
2010	2714624570.5199
2011	2807720230.38887
2012	3434781533.136
2013	3785927677.74958
2014	4088470496.85719
2015	3278733643.10906
2016	2596963478.13738
2017	2850822382.41199