-69.19% is the change from 831 to 256
Calculation steps:
[( 256 - 831 ) ÷ 831] x 100 = -69.19%
Formula
Percentage change = [(256 - 831) / 831] x 100
Subtract the new number by the original number
256 - 831 = -575
-575 ÷ 831 = -0.6919374247894103
-0.6919374247894103 x 100 = -69.19%