Year	current US$
2000	1.9128082
2001	1.91670113
2002	1.94445413
2003	1.9854014
2004	2.02146217
2005	2.05501429
2006	3.30798644
2007	4.3615423
2008	5.08748736
2009	6.38198804
2010	6.9384393
2011	6.90389916
2012	8.55473864
2013	8.28396134
2014	8.4269592
2015	8.64732355
2016	8.74209855
2017	8.43204759
2018	8.46310315
2019	9.94747167
2020	9.49262367
2021	9.79605568