Year	constant 2015 US$
1997	496.66009023485213
1998	509.05352756354637
1999	519.6795449918951
2000	518.082280157006
2001	526.3750934939557
2002	525.4430453441995
2003	537.619872015517
2004	551.4094227907516
2005	563.9300474860091
2006	577.7148208277614
2007	587.0748572726231
2008	593.5270123723956
2009	601.1478572556505
2010	617.3171764872073
2011	602.9320528766939
2012	611.9119169228904
2013	636.1673746015608
2014	645.1844393811109
2015	665.5074729381311
2016	668.8895894370869
2017	674.847512332374
2018	680.0758993340798
2019	697.17914340695
2020	681.4453416084951
2021	700.1878274638575
2022	710.3908104695769
2023	713.7131550552032