-96.69% is the change from 634 to 21
Calculation steps:
[( 21 - 634 ) ÷ 634] x 100 = -96.69%
Formula
Percentage change = [(21 - 634) / 634] x 100
Subtract the new number by the original number
21 - 634 = -613
-613 ÷ 634 = -0.9668769716088328
-0.9668769716088328 x 100 = -96.69%