Year	constant 2015 US$
1999	3059.5039275042463
2000	3459.5861559942
2001	3598.653072305019
2002	3735.8448336283827
2003	3960.791189911241
2004	4416.308681316744
2005	4823.391144840542
2006	5341.533081883381
2007	6011.01588589761
2008	6339.797619946802
2009	5619.6097545689645
2010	6046.199944619236
2011	6461.806521396858
2012	6664.207079138756
2013	6680.427850527141
2014	6712.582558747959
2015	6564.12080267077
2016	6457.705107208849
2017	6717.821385655372
2018	7022.102239376607
2019	7178.255826572672
2020	7010.710094719638
2021	7057.42932858342