Year	current international $
2010	65.3056063062737
2011	62.627373250589
2012	56.8547047937482
2013	53.3991226499962
2014	51.7641633204923
2015	50.2801782378913
2016	47.0211717607873
2017	15.1815844663684
2018	9.77085281568473
2019	6.54147729798181
2020	6.26739968204761
2021	6.47473479851383