Year	current US$
2000	1.53389444
2001	1.30645129
2002	1.16134742
2003	15.9956453
2004	19.92323116
2005	47.66188123
2006	27.14294643
2007	33.57416212
2008	36.04055483
2009	39.89618182
2010	48.00362607
2011	49.25541171
2012	43.40173311
2013	40.62372436
2014	9.48715802
2015	8.35674451
2016	9.47072844
2017	5.8315938
2018	6.48206617
2019	6.19307045
2020	6.55914885
2021	8.30090204