Year	constant 2015 US$
1991	4071.222629831879
1992	4129.480862876525
1993	4172.0252953135605
1994	4289.064113016153
1995	4131.7857965883
1996	4474.619381306097
1997	4398.443966916254
1998	4736.002056976074
1999	4733.773168000167
2000	4782.017658209746
2001	5229.983290425722
2002	5470.522470384904
2003	5414.8441725660805
2004	5248.609906068063
2005	5416.75088858499
2006	5657.173879643654
2007	5251.746371187256
2008	5359.056508202355
2009	5741.880514267484
2010	5964.408952226079
2011	6318.504742586143
2012	6527.463668294381
2013	6772.399913163521
2014	6753.337207166665
2015	6982.854131209848
2016	7072.883046665093
2017	7305.9914046187305
2018	7904.167295198152
2019	8245.436971378032
2020	8667.445533264055
2021	8657.152996163199
2022	8472.597267747602