-17.91% is the change from 631 to 518
Calculation steps:
[( 518 - 631 ) ÷ 631] x 100 = -17.91%
Formula
Percentage change = [(518 - 631) / 631] x 100
Subtract the new number by the original number
518 - 631 = -113
-113 ÷ 631 = -0.179080824088748
-0.179080824088748 x 100 = -17.91%