Year	constant 2015 US$
1991	4466.770013666419
1992	4694.4317086544725
1993	5185.435525950132
1994	5285.527714848696
1995	5347.26358335295
1996	5486.828687295884
1997	5744.340546579477
1998	5790.1922265100075
1999	6087.766809065088
2000	6392.07116371272
2001	6816.406141194699
2002	7209.330627029685
2003	7618.129586576613
2004	7890.439193528966
2005	8531.59574597694
2006	9213.848320046149
2007	10330.183286312838
2008	11024.45439555774
2009	11615.865608733116
2010	12180.700125089945
2011	12810.91379181804
2012	13595.97654738389
2013	13900.495706474407
2014	14302.56857278334
2015	14889.50690789261
2016	15738.371140957326
2017	16791.62028616045
2018	17782.80080385957
2019	18700.47031689527
2020	19078.948997180498
2021	20129.94153689242
2022	20413.114904034315