Year	constant 2015 US$
1977	6037.336572103456
1978	6281.212924099534
1979	6759.331554104976
1980	7279.414033262637
1981	7535.421789920668
1982	7511.182755959137
1983	7892.649803218264
1984	8701.069407384957
1985	9411.373716692326
1986	10547.61848261588
1987	11309.250273093303
1988	11967.862965600998
1989	12664.93125029283
1990	13109.76429351372
1991	13330.72807951779
1992	13271.397762180517
1993	13722.789062724869
1994	14368.709829503036
1995	13475.908279330828
1996	14077.82300027616
1997	14551.99615416155
1998	14956.137628004542
1999	15248.23789756366
2000	15927.90838828504
2001	14972.097527754895
2002	14933.869565372543
2003	15662.833650303717
2004	16384.33444824361
2005	17242.348286465876
2006	19187.030790948218
2007	20687.687129491263
2008	20377.937769292756
2009	17667.84877147301
2010	16062.015811277044
2011	15559.661973122349
2012	15911.096282377064
2013	15668.435510947937
2014	15882.309257207307
2015	15985.541138697094
2016	16526.43613747276
2017	16830.396260284826
2018	17901.040913055916
2019	18357.678822218335
2020	14803.769505746439
2021	15921.09512094603
2022	17335.047039518002
2023	17902.3799187494