Year	current US$
1970	284.1980757673589
1971	340.7586948924064
1972	417.6578565211138
1973	647.6520237912409
1974	851.0271595366675
1975	1047.4734656593535
1976	1358.1543531141992
1977	1576.1823699248064
1978	1384.1312582463145
1979	1691.882091834103
1980	1725.8092008270962
1981	1829.8134070885073
1982	2264.2577540487737
1983	2793.927280015375
1984	2799.6724320990247
1985	3015.044774976812
1986	3451.941029783574
1987	2079.949600462214
1988	1844.3132236569086
1989	1709.5846947610721
1990	1643.2760365182519
1993	746.802149138162
1994	858.1117561194893
1995	1159.2306666404888
1996	1454.500581167332
1997	1390.9716592397604
1998	1371.2637828829913
1999	1386.6384850439904
2000	1246.4937625196349
2001	1491.4731572325675
2002	1563.1809920623068
2003	1833.5794348356542
2004	2196.9516688055373
2005	2548.51409721674
2006	2940.6699483172397
2007	3902.76357478694
2008	4438.476937499395
2009	4613.620270651256
2010	5394.055016314768
2011	6843.277892815751
2012	6821.154395814268
2013	5039.697302071066
2014	4589.081747949943
2015	3972.055859649371
2016	4454.510584222998
2017	4560.098582096406
2018	2782.6335084961306
2019	2463.2880465824314
2020	2082.3857638593145
2021	2999.389490026254