50.2% is the change from 255 to 383
Calculation steps:
[( 383 - 255 ) ÷ 255] x 100 = 50.2%
Formula
Percentage change = [(383 - 255) / 255] x 100
Subtract the new number by the original number
383 - 255 = 128
128 ÷ 255 = 0.5019607843137255
0.5019607843137255 x 100 = 50.2%