Year	constant 2015 US$
1991	19680.60016281548
1992	15105.264620461678
1993	15107.52292350334
1994	13801.881359071782
1995	13946.246773819073
1996	15102.65475861354
1997	10524.151537323374
1998	11219.827549650181
1999	9769.941328909243
2000	10315.068612985322
2001	10425.639619323803
2002	11651.678175119749
2003	11688.70624863114
2004	12065.288621649448
2005	13106.744818679848
2006	13386.989404973194
2007	13966.260039588573
2008	14355.593886790908
2009	14598.463803949988
2010	15565.836221474929
2011	15961.86163688894
2012	15896.070705292215
2013	15416.366586731578
2014	15341.961518428816
2015	15456.960260157342
2016	15719.768118584678
2017	15706.009517082226
2018	16444.14955918698
2019	16818.954069511037
2020	17000.31880394343
2021	18928.402041357458
2022	19988.846296225944