-96.91% is the change from 679 to 21
Calculation steps:
[( 21 - 679 ) ÷ 679] x 100 = -96.91%
Formula
Percentage change = [(21 - 679) / 679] x 100
Subtract the new number by the original number
21 - 679 = -658
-658 ÷ 679 = -0.9690721649484536
-0.9690721649484536 x 100 = -96.91%