Year	current US$
2011	1515.40087890625
2012	1544.28247070313
2013	1543.08703613281
2014	1867.95495605469
2015	1992.76135253906
2016	2353.337890625
2017	2819.8056640625
2018	660.672119140625
2019	632.1044921875
2020	510.933654785156
2021	629.995666503906