Year	constant 2015 US$
1991	229.38883029726728
1992	180.3332410154021
1993	218.37510575584554
1994	206.98659290572036
1995	229.74789322525567
1996	234.07810594528706
1997	250.09983463946554
1998	268.0501661801366
1999	281.9009971722613
2000	243.62744407229798
2001	266.0799704238848
2002	293.6961214985177
2003	304.1523931913412
2004	315.25228230853344
2005	332.46543917911447
2006	362.8670215505198
2007	389.3660509535259
2008	409.36491292536095
2009	426.2525471201389
2010	440.9644682339355
2011	452.3932041227915
2012	451.1081836678389
2013	455.29549676401615
2014	463.52157711492964
2015	469.6709110360832
2016	475.7553308956728
2017	479.2212576397738
2018	482.39638056598704
2019	479.31242138966064
2020	488.0612406637203
2021	491.5188948630899
2022	498.07926171537525