Year	constant 2015 US$
1991	5034.403169136243
1992	5226.955434014095
1993	5107.106796564962
1994	4904.323293030516
1995	4693.050446677211
1996	4619.311861791943
1997	4538.253341622579
1998	4685.710412781201
1999	4715.09077633274
2000	4672.989971838186
2001	4849.977829225608
2002	4871.764197822077
2003	4657.992544232969
2004	5426.145054236597
2005	5552.307043212747
2006	5906.387808602565
2007	6213.048183538016
2008	6529.018657459327
2009	6658.583598178793
2010	6571.645932050975
2011	6537.92009048734
2012	6658.399462418557
2013	6851.4689292447665
2014	6792.529032322294
2015	6660.083806747506
2016	6539.558475292685
2017	6432.777782057313
2018	6401.78000768175
2019	6383.362116203824
2020	6081.23386629169
2021	6158.806464593619
2022	6427.524603756754