-96.83% is the change from 662 to 21
Calculation steps:
[( 21 - 662 ) ÷ 662] x 100 = -96.83%
Formula
Percentage change = [(21 - 662) / 662] x 100
Subtract the new number by the original number
21 - 662 = -641
-641 ÷ 662 = -0.9682779456193353
-0.9682779456193353 x 100 = -96.83%