Year	current US$
2000	8.84117381
2001	7.48763063
2002	7.63434541
2003	8.68789476
2004	9.47306904
2005	12.98313221
2006	17.98692904
2007	19.03179458
2008	17.38210972
2009	16.08456179
2010	16.43171111
2011	16.81079163
2012	16.11491137
2013	18.23019945
2014	21.68364203
2015	22.6134337
2016	23.42508003
2017	25.18937435
2018	23.36776722
2019	20.95047069
2020	21.16574466
2021	24.77562122