Year	current US$
2000	0.19340947
2001	1.11250452
2002	3.02807596
2003	1.80898642
2004	3.13694939
2005	3.78106377
2006	4.08127303
2007	3.19442839
2008	4.28418377
2009	4.93756366
2010	3.40906785
2011	6.10474524
2012	3.78558279
2013	4.00959368
2014	5.75859461
2015	6.43287137
2016	6.45680508
2017	5.54364313
2018	6.46532502
2019	6.06693769
2020	7.85099114
2021	7.13580933