Year	constant 2015 US$
1980	327.36447833915037
1981	331.12885007799565
1982	348.4471022477628
1983	338.0033829381623
1984	324.32076905868297
1985	318.8002506705138
1986	340.210701361817
1987	328.8058349873643
1988	339.155431482955
1989	331.314648447767
1990	323.5644387268637
1991	338.49242876976564
1992	331.51386553046507
1993	332.63704811850175
1994	300.98256330514846
1995	317.21926185428185
1996	342.3934383875064
1997	350.129466845447
1998	370.9081824826914
1999	371.8378954332714
2000	374.6413689454727
2001	387.17046919566457
2002	391.09687433588323
2003	407.7166652935905
2004	413.5914679422827
2005	429.86634201809267
2006	440.2082643312668
2007	443.4130768301844
2008	451.84473898710564
2009	448.8231908746886
2010	471.4270736020825
2011	485.42397416497914
2012	529.2306059196832
2013	530.7060113212026
2014	531.7211952936141
2015	544.8716655694815
2016	573.8624091339623
2017	593.4780495321348
2018	622.1165813593024
2019	648.7698991234457
2020	636.4786856267799
2021	586.2226402514096