28.37% is the change from 638 to 819
Calculation steps:
[( 819 - 638 ) ÷ 638] x 100 = 28.37%
Formula
Percentage change = [(819 - 638) / 638] x 100
Subtract the new number by the original number
819 - 638 = 181
181 ÷ 638 = 0.2836990595611285
0.2836990595611285 x 100 = 28.37%