-90.98% is the change from 255 to 23
Calculation steps:
[( 23 - 255 ) ÷ 255] x 100 = -90.98%
Formula
Percentage change = [(23 - 255) / 255] x 100
Subtract the new number by the original number
23 - 255 = -232
-232 ÷ 255 = -0.9098039215686274
-0.9098039215686274 x 100 = -90.98%