-97.69% is the change from 649 to 15
Calculation steps:
[( 15 - 649 ) ÷ 649] x 100 = -97.69%
Formula
Percentage change = [(15 - 649) / 649] x 100
Subtract the new number by the original number
15 - 649 = -634
-634 ÷ 649 = -0.9768875192604006
-0.9768875192604006 x 100 = -97.69%