-87.93% is the change from 638 to 77
Calculation steps:
[( 77 - 638 ) ÷ 638] x 100 = -87.93%
Formula
Percentage change = [(77 - 638) / 638] x 100
Subtract the new number by the original number
77 - 638 = -561
-561 ÷ 638 = -0.8793103448275862
-0.8793103448275862 x 100 = -87.93%