-7.99% is the change from 638 to 587
Calculation steps:
[( 587 - 638 ) ÷ 638] x 100 = -7.99%
Formula
Percentage change = [(587 - 638) / 638] x 100
Subtract the new number by the original number
587 - 638 = -51
-51 ÷ 638 = -0.07993730407523511
-0.07993730407523511 x 100 = -7.99%