Year	current US$
2000	20.5490409607174
2001	19.139769176121785
2002	18.372398736956786
2003	25.588909832105834
2004	29.543316931457614
2005	30.958361272023236
2006	34.26807365194085
2007	37.4993367874117
2008	40.246805389248586
2009	38.22903187093703
2010	42.70576345450536
2011	46.06745382996519
2012	46.0788726908796
2013	47.94507143138454
2014	47.71634868763751
2015	43.721288943512945
2016	39.943413974356055
2017	39.3184407836604
2018	37.831150523603846
2019	36.548835512749484
2020	33.92723715936824
2021	38.957238863492314