-39.35% is the change from 831 to 504
Calculation steps:
[( 504 - 831 ) ÷ 831] x 100 = -39.35%
Formula
Percentage change = [(504 - 831) / 831] x 100
Subtract the new number by the original number
504 - 831 = -327
-327 ÷ 831 = -0.3935018050541516
-0.3935018050541516 x 100 = -39.35%