-97.69% is the change from 650 to 15
Calculation steps:
[( 15 - 650 ) ÷ 650] x 100 = -97.69%
Formula
Percentage change = [(15 - 650) / 650] x 100
Subtract the new number by the original number
15 - 650 = -635
-635 ÷ 650 = -0.9769230769230769
-0.9769230769230769 x 100 = -97.69%