Year	current US$
2000	0.46954169
2001	0.93544552
2002	1.20323057
2003	1.07303108
2004	3.33962305
2005	2.60829245
2006	2.99206661
2007	4.58010586
2008	4.56111531
2009	5.58198012
2010	5.60466254
2011	6.24822353
2012	8.51110814
2013	2.58143948
2014	3.65206025
2015	4.00278684
2016	4.5091576
2017	4.63869384
2018	5.00497057
2019	5.46286397
2020	4.97427924
2021	5.12378809