Year	current US$
1973	3.3886931402894143
1974	54.68787761246567
1975	7.696055477816297
1976	1.5217390829238333
1977	3.0953248572058647
1978	2.178198717350852
1979	9.601168620757216
1980	32.67152388857109
1981	34.450242607295166
1982	44.21345355258582
1983	33.02211735193233
1984	41.81622722951102
1985	45.219213038650665
1986	51.34969043820996
1987	128.33649463252146
1988	111.00890399250233
1989	125.37353646292114
1990	129.37413578857715
1991	128.69922363440935
1992	123.31100562663653
1993	101.22329067464017
1994	55.056370357776224
1995	59.564150097868705
1996	52.903240786689736
1997	39.45043411933946
1998	35.189460704697694
1999	30.899394944526428
2000	31.052138185316736
2001	18.407551783222154
2002	26.720062084072456
2003	26.504373671363247
2004	35.27539570587738
2005	44.09489372138134
2006	28.94795451876669
2007	34.74864538329229
2008	33.79998117343641
2009	32.10735635194225
2010	77.72328399818022
2011	21.448765177566514
2012	12.105867960806393
2013	3.7220415714579067
2014	0.40148765149520493
2015	5.560616115629756
2016	4.946648450057759
2017	4.7770238439937165
2018	4.473763433900909
2019	40.404859915867746
2020	3.815672421453157
2021	7.812949585836414
2022	6.674993674384384