Year	constant 2015 US$
1991	24614.67680748109
1992	29943.087209174308
1993	21675.986395138687
1994	17107.25121987071
1995	16364.77911569443
1996	16338.142719966037
1997	14825.245518552272
1998	16597.31873427095
1999	11664.864954042627
2000	12260.383817992431
2001	12874.816576234898
2002	16446.608264812927
2003	17702.227927304826
2004	18531.54080088802
2005	18354.31560917494
2006	19992.039651230887
2007	18169.714304631252
2008	26014.101252291046
2009	29283.935237904312
2010	31038.914468124884
2011	32467.88975608432
2012	29872.32250715698
2013	27658.27318824955
2014	26357.93650225494
2015	24397.038884928243
2016	23916.46937043957
2017	24195.254844059466
2018	22220.28422023836
2019	23867.363850893275
2020	24127.284395966126
2021	26275.158349715424
2022	26786.317306026063