Year	current US$
2000	2.68814455
2001	2.8750116
2002	3.03086922
2003	4.13974947
2004	4.26395298
2005	3.93367926
2006	3.21517521
2007	2.90521825
2008	4.61297911
2009	3.57127921
2010	3.59017102
2011	5.55018352
2012	5.95383274
2013	5.61365165
2014	4.75410845
2015	5.9915516
2016	6.66902265
2017	4.90446136
2018	3.73493391
2019	2.71156536
2020	6.79579749
2021	3.98033755