-21.18% is the change from 255 to 201
Calculation steps:
[( 201 - 255 ) ÷ 255] x 100 = -21.18%
Formula
Percentage change = [(201 - 255) / 255] x 100
Subtract the new number by the original number
201 - 255 = -54
-54 ÷ 255 = -0.21176470588235294
-0.21176470588235294 x 100 = -21.18%