Year	current US$
2000	32.24752007
2001	27.62905964
2002	26.58947284
2003	33.20534741
2004	32.62513348
2005	31.4189254
2006	26.82283065
2007	44.47376065
2008	39.49281024
2009	24.05530142
2010	19.32126698
2011	20.09901458
2012	18.71423715
2013	36.96969406
2014	31.99825889
2015	25.18311253
2016	20.95316961
2017	42.72952468
2018	35.81817797
2019	39.10537301
2020	20.54472253
2021	24.50050328