-39.51% is the change from 820 to 496
Calculation steps:
[( 496 - 820 ) ÷ 820] x 100 = -39.51%
Formula
Percentage change = [(496 - 820) / 820] x 100
Subtract the new number by the original number
496 - 820 = -324
-324 ÷ 820 = -0.3951219512195122
-0.3951219512195122 x 100 = -39.51%