Year	current US$
2000	9.1193943
2001	7.92787647
2002	7.34832239
2003	17.29731369
2004	20.29362106
2005	25.10174942
2006	27.24308205
2007	33.58434677
2008	40.0471344
2009	44.08419418
2010	48.02530289
2011	51.65081787
2012	57.216465
2013	47.7094574
2014	50.62351608
2015	48.80509567
2016	50.70415497
2017	48.34190369
2018	51.54394531
2019	51.18757629
2020	57.91234207
2021	60.2185936