Year	current international $
2000	6.22599894819177
2001	5.2942190828805
2002	5.876123105762
2003	2.88183106391128
2004	3.89606736132606
2005	4.24334688714912
2006	3.85144010929101
2007	6.33525760632722
2008	8.2439637780431
2009	11.345487847284
2010	12.3961696570947
2011	15.5672419781903
2012	17.0887719733047
2013	4.3683437625229
2014	10.7901839094561
2015	14.6832667298402
2016	18.600681521488
2017	20.838058778958
2018	25.0695777972526
2019	19.0907182074973
2020	13.5555181315882
2021	16.9761383952296