-83.9% is the change from 857 to 138
Calculation steps:
[( 138 - 857 ) ÷ 857] x 100 = -83.9%
Formula
Percentage change = [(138 - 857) / 857] x 100
Subtract the new number by the original number
138 - 857 = -719
-719 ÷ 857 = -0.838973162193699
-0.838973162193699 x 100 = -83.9%