-18.83% is the change from 823 to 668
Calculation steps:
[( 668 - 823 ) ÷ 823] x 100 = -18.83%
Formula
Percentage change = [(668 - 823) / 823] x 100
Subtract the new number by the original number
668 - 823 = -155
-155 ÷ 823 = -0.18833535844471447
-0.18833535844471447 x 100 = -18.83%