-9.56% is the change from 638 to 577
Calculation steps:
[( 577 - 638 ) ÷ 638] x 100 = -9.56%
Formula
Percentage change = [(577 - 638) / 638] x 100
Subtract the new number by the original number
577 - 638 = -61
-61 ÷ 638 = -0.09561128526645768
-0.09561128526645768 x 100 = -9.56%