Year	constant 2015 US$
1991	6685.031210443111
1992	7029.6934862712305
1993	7119.281020306246
1994	7914.557009263745
1995	7707.322822831515
1996	7966.47647259996
1997	6639.842320933814
1998	5738.232751720464
1999	5883.768886850254
2000	5360.274082939296
2001	4700.379074414175
2002	4568.4201638034765
2003	3945.582382961563
2004	3924.0129593511474
2005	3865.5454153179744
2006	3876.4240606293206
2007	3505.869283069272
2008	3357.4384270623996
2009	2979.990725420707
2010	2815.5189606200497
2011	2886.579687614481
2012	3094.229007982046
2013	3186.650322747085
2014	3279.5779102125944
2015	3395.749635841719
2016	3033.5586412831826
2017	3424.9608250426463
2018	3601.6964848245857
2019	3774.961238202348
2020	3973.023203436065
2021	4022.749955895857
2022	4058.6416434277235