Year	current US$
2000	1.15754857
2001	4.91339472
2002	3.59321219
2003	3.03095571
2004	3.76166745
2005	4.42423171
2006	9.35868924
2007	12.05193261
2008	9.16596509
2009	15.75725745
2010	11.7988022
2011	12.51600051
2012	8.00102029
2013	3.9468512
2014	1.3143911
2015	3.55239261
2016	3.01490962
2017	5.23040959
2018	6.36911278
2019	2.033736
2020	3.41819758
2021	1.10922132