Year	current US$
2000	454.43609619
2001	341.18649292
2002	291.11621094
2003	266.06005859
2004	210.49307251
2005	320.3678894
2006	354.24862671
2007	572.72601318
2008	791.19970703
2009	563.16577148
2010	614.13409424
2011	659.43389893
2012	859.04864502
2013	818.11560059
2014	746.35699463
2015	959.48846436
2016	957.28594971
2017	1092.87634277
2018	1175.68676758
2019	1158.77087402
2020	1318.16503906
2021	1529.51916504