Year	constant 2015 US$
1991	2684.84650300807
1992	2411.919795166335
1993	2659.194810597526
1994	2394.9802706502032
1995	2467.0538814075835
1996	2778.1747012952615
1997	2471.346091175371
1998	2413.6016807436
1999	2254.23398798407
2000	2481.774584898566
2001	2568.965827218838
2002	2690.2948115705535
2003	2972.8696042856423
2004	3459.4674627571417
2005	3657.6766765747493
2006	3997.908873621334
2007	4323.409038270804
2008	4834.45359480776
2009	4983.529031339211
2010	5325.232352037803
2011	5910.145789372433
2012	6550.110697580868
2013	6573.019196716591
2014	7053.570229179419
2015	7177.2159086843385
2016	7842.402843960453
2017	7448.949332041861
2018	5916.812840730499
2019	6217.499605401844
2020	6649.7289656111025
2021	6397.182269191794
2022	6742.560193606298