Year	constant 2015 US$
1988	1699.7761616405512
1989	1617.6637201585343
1990	1604.685014227529
1991	1603.0227316036862
1992	1488.285445359094
1993	1380.2406966282697
1994	1196.1547833881314
1995	1293.6433746105029
1996	1324.5573775591154
1997	1334.3196981889341
1998	1337.4958227748348
1999	1347.465170514031
2000	1331.6269322975688
2001	1303.2636972826267
2002	1293.199341668603
2003	1314.6789239534903
2004	1276.719682880371
2005	1290.390642060413
2006	1299.0808880430225
2007	1337.0244592344627
2008	1350.837870285452
2009	1408.4377732802009
2010	1314.6998336684414
2011	1367.5595304282756
2012	1354.923541065244
2013	1389.9863613173839
2014	1410.854931704222
2015	1409.5612227672834
2016	1416.1800393487947
2017	1432.5273163706509
2018	1435.3811133407885
2019	1392.4411318486686
2020	1326.8494293547153
2021	1285.886945214223
2022	1249.3684815830954
2023	1210.2084890304614