Year	constant 2015 US$
1990	8353.529645009214
1991	7866.018640841468
1992	6200.513308835564
1993	5219.049892866635
1994	4742.151547034149
1995	4936.020215434404
1996	5230.260191549177
1997	5706.895260758754
1998	6178.123821338397
1999	6151.082963624421
2000	6423.420676224443
2001	6899.236834412121
2002	7424.394824244811
2003	8275.803447580305
2004	8919.081749490124
2005	9766.487647165093
2006	10659.400210699785
2007	11984.923294106395
2008	12425.398099920674
2009	10699.78945816287
2010	11106.950214542436
2011	12046.72138586938
2012	12678.692685987913
2013	13262.334462077057
2014	13850.000127119862
2015	14263.964577349474
2016	14810.251778627327
2017	15661.996253677504
2018	16443.585287577593
2019	17256.408152190772
2020	17247.543693303927
2021	18292.532850787207
2022	18535.07796634781
2023	18213.83425299059