99.22% is the change from 257 to 512
Calculation steps:
[( 512 - 257 ) ÷ 257] x 100 = 99.22%
Formula
Percentage change = [(512 - 257) / 257] x 100
Subtract the new number by the original number
512 - 257 = 255
255 ÷ 257 = 0.9922178988326849
0.9922178988326849 x 100 = 99.22%