-96.9% is the change from 677 to 21
Calculation steps:
[( 21 - 677 ) ÷ 677] x 100 = -96.9%
Formula
Percentage change = [(21 - 677) / 677] x 100
Subtract the new number by the original number
21 - 677 = -656
-656 ÷ 677 = -0.9689807976366323
-0.9689807976366323 x 100 = -96.9%