-39.71% is the change from 831 to 501
Calculation steps:
[( 501 - 831 ) ÷ 831] x 100 = -39.71%
Formula
Percentage change = [(501 - 831) / 831] x 100
Subtract the new number by the original number
501 - 831 = -330
-330 ÷ 831 = -0.3971119133574007
-0.3971119133574007 x 100 = -39.71%