21.79% is the change from 638 to 777
Calculation steps:
[( 777 - 638 ) ÷ 638] x 100 = 21.79%
Formula
Percentage change = [(777 - 638) / 638] x 100
Subtract the new number by the original number
777 - 638 = 139
139 ÷ 638 = 0.21786833855799373
0.21786833855799373 x 100 = 21.79%