20.62% is the change from 257 to 310
Calculation steps:
[( 310 - 257 ) ÷ 257] x 100 = 20.62%
Formula
Percentage change = [(310 - 257) / 257] x 100
Subtract the new number by the original number
310 - 257 = 53
53 ÷ 257 = 0.20622568093385213
0.20622568093385213 x 100 = 20.62%