Year	current international $
2000	3.74875294124087
2001	4.20192087631202
2002	4.53105382680145
2003	5.30635456967233
2004	6.19358831552521
2005	6.72909666310721
2006	7.75986515951249
2007	8.44164481161605
2008	8.56291641535244
2009	10.2023957599995
2010	17.3886776901162
2011	17.0939774181283
2012	19.5686587716223
2013	16.7076877003024
2014	18.1492829404151
2015	17.4244423918312
2016	18.8062126470445
2017	20.6791497250666
2018	21.0994534014919
2019	18.7201242656454
2020	19.4065700045621
2021	12.9013784900457