Year	current US$
2000	246.51157906
2001	229.12124237
2002	212.79530148
2003	196.85642662
2004	180.85412131
2005	165.39614407
2006	180.58853672
2007	194.76955088
2008	208.93163116
2009	223.30007861
2010	249.48935117
2011	260.07578414
2012	222.28472568
2013	215.62132348
2014	205.1288537
2015	189.20237143
2016	207.05776853
2017	223.98144417
2018	262.85236521
2019	240.22552814
2020	158.35734952
2021	106.624299