-39.06% is the change from 256 to 156
Calculation steps:
[( 156 - 256 ) ÷ 256] x 100 = -39.06%
Formula
Percentage change = [(156 - 256) / 256] x 100
Subtract the new number by the original number
156 - 256 = -100
-100 ÷ 256 = -0.390625
-0.390625 x 100 = -39.06%