-35.16% is the change from 256 to 166
Calculation steps:
[( 166 - 256 ) ÷ 256] x 100 = -35.16%
Formula
Percentage change = [(166 - 256) / 256] x 100
Subtract the new number by the original number
166 - 256 = -90
-90 ÷ 256 = -0.3515625
-0.3515625 x 100 = -35.16%