-97.62% is the change from 631 to 15
Calculation steps:
[( 15 - 631 ) ÷ 631] x 100 = -97.62%
Formula
Percentage change = [(15 - 631) / 631] x 100
Subtract the new number by the original number
15 - 631 = -616
-616 ÷ 631 = -0.9762282091917591
-0.9762282091917591 x 100 = -97.62%