Year	constant 2015 US$
1991	4164.4571481259045
1992	4239.903866430553
1993	4430.517720164549
1994	4456.739167526794
1995	4135.734928924168
1996	4041.629673563287
1997	4132.138672580487
1998	4341.964886729967
1999	4644.01398848583
2000	4800.489762158851
2001	5029.857682014432
2002	5441.853389250463
2003	5915.35380925045
2004	6047.909902006791
2005	6232.861299325661
2006	6338.336631477078
2007	6414.290449653936
2008	6343.496005546347
2009	5926.219653185239
2010	5865.883602432792
2011	5932.910263177972
2012	5830.093251720255
2013	5837.884363960468
2014	5994.831674325198
2015	6236.606867678946
2016	6549.962045809448
2017	6896.246882408395
2018	7257.692246486981
2019	7623.806336893811
2020	7551.684616202311
2021	7930.092227252875
2022	8548.24108913737
2023	8381.994338154716