Year	current US$
2001	2186.5703125
2002	2214.66992188
2003	2440.29370117
2004	2868.36132813
2005	2958.65527344
2006	3132.23461914
2007	3672.22583008
2008	4235.84814453
2009	4110.07666016
2010	3695.15039063
2011	4504.63085938
2012	4353.61474609
2013	4154.9296875
2014	4161.48681641
2015	3564.85253906
2016	3656.28491211
2017	3706.97045898
2018	4012.65405273
2019	3854.09521484
2020	3842.77392578
2021	4131.94189453