Year	constant 2015 US$
1991	217.5635105008833
1992	193.66316726554595
1993	209.70513081732489
1994	212.41408009511062
1995	209.72481488005047
1996	227.8460892556871
1997	249.23478502057714
1998	266.89925012313563
1999	292.31707372972585
2000	283.78913128237406
2001	310.55304117022837
2002	310.95781788640437
2003	351.5305600748866
2004	372.0200859535351
2005	377.79329884158165
2006	393.70126570193304
2007	417.97372102372987
2008	436.83455203245404
2009	463.7953674281974
2010	477.32571665376304
2011	503.8182891610829
2012	534.6847587669461
2013	553.2178497787738
2014	573.309930218349
2015	592.6575587040317
2016	600.9383577436645
2017	591.6294065246556
2018	600.5424066346725
2019	598.3048572346453
2020	572.717698945296
2021	569.0931829275144
2022	539.3311580595782