Year	constant 2015 US$
1970	11624.598354398604
1971	11964.885481904686
1972	12458.817991916072
1973	13065.143662670134
1974	13025.703884050046
1975	12870.545883044462
1976	13391.349935152539
1977	13670.892676172389
1978	14131.212352140617
1979	14521.211769183828
1980	14436.250614469589
1981	14184.665699087162
1982	14241.093438841048
1983	14452.131678160249
1984	14784.488799813054
1985	15126.646309413127
1986	15898.198774405706
1987	16340.830679284883
1988	17002.033229486406
1989	17547.17705689203
1990	18097.191080538978
1991	18385.97833617807
1992	18581.664728442338
1993	18354.75439259411
1994	18793.85418434133
1995	19289.10024811701
1996	19630.050961850637
1997	20121.33510632118
1998	20790.670890484984
1999	21383.953160287696
2000	21906.651751925652
2001	22308.704058359606
2002	22464.078678147944
2003	22618.924505875508
2004	23173.73768901506
2005	23483.164826694298
2006	24195.49531162824
2007	24847.961981085144
2008	24588.009353651258
2009	23612.510227121922
2010	24019.90557877626
2011	24337.276962430806
2012	24048.735125412564
2013	24074.36306273861
2014	24502.212155972295
2015	25112.446479110582
2016	25741.180045421526
2017	26376.50857590166
2018	26847.674830953343
2019	27276.135250085063
2020	25395.540553613246
2021	26811.584076361538