Year	constant 2015 US$
1991	18964.914797134275
1992	20518.0397209775
1993	20882.047861315405
1994	20893.285173517113
1995	20243.732658809993
1996	19912.018103134626
1997	20193.14841535404
1998	19144.07703774496
1999	19833.621414634054
2000	19797.222766552328
2001	19004.318743349377
2002	18980.49234754083
2003	18946.540781584452
2004	18489.982390545552
2005	18243.832078682623
2006	17284.674578266786
2007	17015.133983440275
2008	16000.244746832337
2009	15082.670900897905
2010	14766.881840671027
2011	14157.983428559268
2012	14220.666276054171
2013	14188.390269314828
2014	14319.472252787047
2015	14092.145636584692
2016	13574.996286139622
2017	12833.255004592742
2018	13259.455842905381
2019	13316.957675045282
2020	12094.573857860807
2021	13636.627980194358
2022	14096.980578932626