Year	constant 2015 US$
1991	17449.605641075803
1992	17571.64764856009
1993	17106.998554643706
1994	15953.327372800719
1995	16540.87135420985
1996	16870.760095028712
1997	16472.8200777227
1998	17263.342180280782
1999	16037.28703762161
2000	15366.571369330622
2001	15143.637020088629
2002	15528.996721283884
2003	16317.281591643658
2004	16901.800003530065
2005	17622.472400533865
2006	18176.450841286765
2007	18748.714502960698
2008	18967.035083708208
2009	19855.7408790569
2010	19863.710191506285
2011	20280.46212335317
2012	21609.141224271752
2013	21559.541872969407
2014	21575.10930907107
2015	20073.72330864107
2016	19006.73284040793
2017	17820.486463890655
2018	18936.21218609129
2019	20096.27672705546
2020	18008.47576983621
2021	17824.982160283984
2022	17943.703878259115