-89.65% is the change from 831 to 86
Calculation steps:
[( 86 - 831 ) ÷ 831] x 100 = -89.65%
Formula
Percentage change = [(86 - 831) / 831] x 100
Subtract the new number by the original number
86 - 831 = -745
-745 ÷ 831 = -0.8965102286401926
-0.8965102286401926 x 100 = -89.65%