-92.19% is the change from 256 to 20
Calculation steps:
[( 20 - 256 ) ÷ 256] x 100 = -92.19%
Formula
Percentage change = [(20 - 256) / 256] x 100
Subtract the new number by the original number
20 - 256 = -236
-236 ÷ 256 = -0.921875
-0.921875 x 100 = -92.19%