27.9% is the change from 638 to 816
Calculation steps:
[( 816 - 638 ) ÷ 638] x 100 = 27.9%
Formula
Percentage change = [(816 - 638) / 638] x 100
Subtract the new number by the original number
816 - 638 = 178
178 ÷ 638 = 0.27899686520376177
0.27899686520376177 x 100 = 27.9%