Year	current US$
2000	14.253536868941985
2001	12.921089223193372
2002	13.950332104965547
2003	15.723671018033862
2004	18.239050012107406
2005	21.04740784213693
2006	24.830496360277994
2007	29.96695907563328
2008	34.074084463650934
2009	35.04338749032624
2010	35.5502491197293
2011	36.44003035687077
2012	36.81899465889193
2013	39.15024234677993
2014	40.86819808469789
2015	38.83629121653919
2016	36.84033766154225
2017	34.72034170170527
2018	32.53224237505107
2019	33.36981966475935
2020	35.33947903768302
2021	36.50028655819541