Year	current US$
2000	15.614040452934027
2001	15.410662759897736
2002	16.538271709324697
2003	18.42972621194044
2004	20.89155640200072
2005	23.529251548108512
2006	26.81656912895274
2007	31.06600935458107
2008	35.93298653608739
2009	37.318501748484515
2010	39.19935435580031
2011	42.525697400065354
2012	43.58605458488205
2013	47.08475808836745
2014	48.707483652618066
2015	47.95060501676021
2016	47.784832945049544
2017	47.730388217860714
2018	48.113920236367726
2019	50.00807067125416
2020	51.47008359726493
2021	55.33622760564264