Year	current US$
2000	37.87960669
2001	74.68108439
2002	79.48165249
2003	130.16071137
2004	224.90765103
2005	247.97262697
2006	277.65402118
2007	188.53500612
2008	194.03821467
2009	132.81110858
2010	152.07150179
2011	184.16197207
2012	210.08998224
2013	242.72689745
2014	288.20221742
2015	277.8852077
2016	310.87020256
2017	339.88378728
2018	351.20775329
2019	376.25409254
2020	372.34688817
2021	444.05987001