Year	current US$
2000	2.5214311002667285
2001	2.00583109013553
2002	2.2760965516004625
2003	3.7262733737651867
2004	4.956415769021447
2005	7.568363592663524
2006	7.657592330186783
2007	8.571343038408182
2008	9.70258442390998
2009	10.388634200184512
2010	11.623079021484331
2011	12.822064897302361
2012	12.42663692407858
2013	13.821488340230577
2014	11.901999657639198
2015	10.40452713069355
2016	9.74259867028867
2017	9.681107980763123
2018	9.999386699330163
2019	10.677680652410123
2020	9.96068661541652
2021	11.381919066037819
