-39.56% is the change from 857 to 518
Calculation steps:
[( 518 - 857 ) ÷ 857] x 100 = -39.56%
Formula
Percentage change = [(518 - 857) / 857] x 100
Subtract the new number by the original number
518 - 857 = -339
-339 ÷ 857 = -0.39556592765460913
-0.39556592765460913 x 100 = -39.56%