Year	constant 2015 US$
1991	12072.453225224881
1992	12213.18053853609
1993	12754.501509508113
1994	13193.237089817792
1995	13141.969763627145
1996	13171.139973630126
1997	13741.570696647266
1998	14063.20449571524
1999	14235.783008803306
2000	14546.57486350851
2001	14763.133555964792
2002	15151.888167561676
2003	15793.038874414593
2004	16357.699494331055
2005	16594.062287667744
2006	17408.63142297351
2007	17546.67829197722
2008	17232.674041661085
2009	16639.332988102266
2010	16524.041241401083
2011	16451.93590091961
2012	16586.26449881871
2013	16818.931912098156
2014	16811.42371671558
2015	17253.113616565115
2016	17679.245198024524
2017	17768.17076217282
2018	18193.236253095227
2019	18544.30962017354
2020	18723.38643847644
2021	18461.09164037467
2022	19412.961865039382