Year	current US$
2000	1.130007415403063
2001	1.212560097147011
2002	1.6752165179445069
2003	1.4884497388198217
2004	3.9077538458569734
2005	1.9259585736541631
2006	1.821540052991924
2007	1.770856075389558
2008	2.32341158652924
2009	2.5684632408562886
2010	3.330392601180047
2011	4.703997137195909
2012	3.880050983996942
2013	2.972786300644697
2014	4.173419817203791
2015	3.34986057468873
2016	2.465341223581059
2017	2.323530197041744
2018	2.0475034972459487
2019	1.9179410016894236
2020	1.6208575889131622
2021	3.0791802812562343