Year	current US$
2000	2.5214311002667285
2001	2.00583109013553
2002	2.276096551600463
2003	3.7262733737651867
2004	4.956415769021448
2005	7.568363592663523
2006	7.657592330186783
2007	8.571343038408182
2008	9.70258442390998
2009	10.38863420018451
2010	11.623079021484335
2011	12.822064897302361
2012	12.426636924078577
2013	13.821488340230571
2014	11.9019996576392
2015	10.40452713069355
2016	9.742598670288672
2017	9.681107980763121
2018	9.999386699330167
2019	10.677680652410125
2020	9.96068661541652
2021	11.381919066037819