21.47% is the change from 638 to 775
Calculation steps:
[( 775 - 638 ) ÷ 638] x 100 = 21.47%
Formula
Percentage change = [(775 - 638) / 638] x 100
Subtract the new number by the original number
775 - 638 = 137
137 ÷ 638 = 0.21473354231974923
0.21473354231974923 x 100 = 21.47%