-68.47% is the change from 812 to 256
Calculation steps:
[( 256 - 812 ) ÷ 812] x 100 = -68.47%
Formula
Percentage change = [(256 - 812) / 812] x 100
Subtract the new number by the original number
256 - 812 = -556
-556 ÷ 812 = -0.6847290640394089
-0.6847290640394089 x 100 = -68.47%