Year	current US$
1970	2281.937165675886
1971	2487.2000234171614
1972	2853.5571474081576
1973	3409.388675502916
1974	3713.7763316753753
1975	4100.136117166069
1976	4406.2360899932055
1977	4915.32958440705
1978	5858.974622173161
1979	6604.318726770341
1980	7206.3327465612665
1981	7276.859834813467
1982	7127.132055045017
1983	7257.320635575143
1984	7587.65968965735
1985	7923.057461280719
1986	9539.83626973136
1987	10974.142707400877
1988	12351.965605824827
1989	12742.466777319281
1990	14152.716627781601
1991	14815.043715554944
1992	15767.182774607127
1993	15773.396046423404
1994	16818.045424781547
1995	18348.55169704061
1996	18439.68373790939
1997	18113.22328605438
1998	18259.663707049865
1999	18968.45459137007
2000	19236.718146074145
2001	18932.725605973545
2002	19555.2024263626
2003	21652.309305205457
2004	23989.3604462856
2005	25155.71648881577
2006	26442.58089351263
2007	28507.040626631988
2008	29555.552243807917
2009	27429.618600505448
2010	28896.549604414227
2011	30951.332048039403
2012	30896.518263944814
2013	31126.984641141407
2014	31690.969471902932
2015	29775.853120553467
2016	30053.878416938325
2017	31246.18349060853
2018	32789.95373196376
2019	32874.42795362816
2020	31566.584414703444
2021	34749.73038370367