-30.45% is the change from 821 to 571
Calculation steps:
[( 571 - 821 ) ÷ 821] x 100 = -30.45%
Formula
Percentage change = [(571 - 821) / 821] x 100
Subtract the new number by the original number
571 - 821 = -250
-250 ÷ 821 = -0.30450669914738127
-0.30450669914738127 x 100 = -30.45%