-30.37% is the change from 820 to 571
Calculation steps:
[( 571 - 820 ) ÷ 820] x 100 = -30.37%
Formula
Percentage change = [(571 - 820) / 820] x 100
Subtract the new number by the original number
571 - 820 = -249
-249 ÷ 820 = -0.30365853658536585
-0.30365853658536585 x 100 = -30.37%