Year	constant 2015 US$
1991	18667.00963281319
1992	18539.808336197315
1993	18187.52269573648
1994	20662.423224504433
1995	21332.24384083873
1996	21234.473110829327
1997	21977.680826542524
1998	22014.925662550726
1999	22145.87359709639
2000	22482.471514513178
2001	22635.981292985223
2002	22500.684283490777
2003	22467.16039843171
2004	22551.84512690218
2005	22835.90470048654
2006	23031.027279830323
2007	23739.931141557394
2008	23912.217748164418
2009	23515.645944578595
2010	23877.39788513733
2011	24167.945763084525
2012	24418.9743093526
2013	24424.96616911785
2014	24438.877689952733
2015	31938.02832398026
2016	24742.82341298077
2017	25160.052274284506
2018	25435.118237461495
2019	25691.787029534687
2020	25448.80659229609
2021	26286.613225548106
2022	26599.28578070684
