Year	current US$
2000	37.89381038
2001	36.81890631
2002	38.94269153
2003	46.7078986
2004	51.52246214
2005	51.66444004
2006	52.25946092
2007	57.16658926
2008	61.4768399
2009	58.40431993
2010	55.59030101
2011	51.84635531
2012	52.17946123
2013	55.38798287
2014	55.20940057
2015	45.64292023
2016	45.00380437
2017	47.57782227
2018	50.05427984
2019	48.10261995
2020	54.67891245
2021	55.03460431