-47.5% is the change from 821 to 431
Calculation steps:
[( 431 - 821 ) ÷ 821] x 100 = -47.5%
Formula
Percentage change = [(431 - 821) / 821] x 100
Subtract the new number by the original number
431 - 821 = -390
-390 ÷ 821 = -0.47503045066991473
-0.47503045066991473 x 100 = -47.5%