Year	current US$
1970	4.372833041268225
1971	4.798925021161071
1972	5.363018801275767
1973	6.252388339144175
1974	9.649909424308577
1975	12.955046332530653
1976	11.800997260183884
1977	13.557813342000241
1978	17.600015242462646
1979	22.32687869660605
1980	24.866173319741424
1981	23.207166602564538
1982	23.23791354892903
1983	22.14352611045312
1984	22.113105190538818
1985	25.074196352912317
1986	30.426274278153617
1987	33.815360650176665
1988	37.380974133519494
1989	37.58605257414669
1990	43.863565499715335
1991	44.652653481987166
1992	44.73777704391699
1993	38.759481340227545
1994	42.848911198569304
1995	41.68099403200651
1996	34.54283571300147
1997	29.3375306936232
1998	28.61959439295435
1999	26.682199380217675
2000	24.608721575560953
2001	28.796004676532714
2002	36.080539398172505
2003	46.44541924807868
2004	48.20005922966993
2005	48.729917982404956
2006	53.6156424927615
2007	59.91759516376406
2008	62.63592943173875
2009	67.66859103830133
2010	69.68599384726218
2011	68.03816458471286
2012	63.32859755336241
2013	59.124013941976045
2014	54.389193467508086
2015	51.4421605893959
2016	48.91697142989453
2017	51.607028730899216
2018	51.88964849963974
2019	51.865583044765565
2020	64.78224620149054
2021	57.60698074320091