Year	current US$
2000	16.86105351554763
2001	16.41581593868076
2002	17.26454415939931
2003	21.129600907740404
2004	23.803770343532435
2005	27.542761383201963
2006	32.35739994186381
2007	36.456320767502426
2008	41.38481655575806
2009	40.87941131223148
2010	44.241741395535705
2011	47.97877195104557
2012	50.43765599174084
2013	54.919884287349404
2014	57.18851495818243
2015	55.449927284231954
2016	53.73094755416075
2017	52.71808642039594
2018	52.247808027938866
2019	53.551188092239
2020	55.14965342127921
2021	61.37062447541578