-37.93% is the change from 638 to 396
Calculation steps:
[( 396 - 638 ) ÷ 638] x 100 = -37.93%
Formula
Percentage change = [(396 - 638) / 638] x 100
Subtract the new number by the original number
396 - 638 = -242
-242 ÷ 638 = -0.3793103448275862
-0.3793103448275862 x 100 = -37.93%