20.31% is the change from 256 to 308
Calculation steps:
[( 308 - 256 ) ÷ 256] x 100 = 20.31%
Formula
Percentage change = [(308 - 256) / 256] x 100
Subtract the new number by the original number
308 - 256 = 52
52 ÷ 256 = 0.203125
0.203125 x 100 = 20.31%