Year	current US$
2000	1.18768133
2001	2.54796546
2002	31.55428852
2003	12.45983409
2004	22.16042636
2005	23.9123289
2006	27.747349
2007	24.71705544
2008	29.08171086
2009	46.30778708
2010	23.83887729
2011	37.73010845
2012	37.16149642
2013	36.65122359
2014	40.01030653
2015	26.45512225
2016	24.45330237
2017	21.08522741
2018	16.44782418
2019	21.72544487
2020	22.34535156
2021	28.23346495