Year	current US$
1971	996.4637156350892
1972	1167.499533797863
1973	1515.5101403686774
1974	2061.2244389216025
1975	2260.6321058738354
1976	2428.7319407564473
1977	2468.127727284299
1978	2788.21155995062
1979	3402.3574070847535
1980	4009.0614376686462
1981	4482.7449530520935
1982	4876.335478857918
1983	5486.684196816
1984	6157.1260659217905
1985	5975.0440495568455
1986	5659.443952927646
1987	6065.892260045574
1988	7395.316082308543
1989	8777.944901290082
1990	10038.869804407752
1991	12202.454542901734
1992	13795.02974810326
1993	15241.773423849463
1994	18683.653146838857
1995	21917.98651669173
1996	22712.22661299448
1997	23608.05212080311
1998	18971.848758599215
1999	18719.43405831992
2000	20280.94915352767
2001	18081.47198725857
2002	18040.140873817
2003	19054.05927342923
2004	21398.133632543253
2005	23539.88370565376
2006	27931.84202574088
2007	32959.45037082997
2008	32449.60341973978
2009	30670.109563693204
2010	40278.664993193655
2011	44678.09977841741
2012	45310.39946181894
2013	45715.85553784865
2014	47257.567984783695
2015	43257.86202273188
2016	44514.64595308655
2017	47208.510797801166
2018	48006.335096509894
2019	46216.418101956515
2020	40860.48066304502
2021	50689.99270118946