-97.71% is the change from 655 to 15
Calculation steps:
[( 15 - 655 ) ÷ 655] x 100 = -97.71%
Formula
Percentage change = [(15 - 655) / 655] x 100
Subtract the new number by the original number
15 - 655 = -640
-640 ÷ 655 = -0.9770992366412213
-0.9770992366412213 x 100 = -97.71%