-65.9% is the change from 821 to 280
Calculation steps:
[( 280 - 821 ) ÷ 821] x 100 = -65.9%
Formula
Percentage change = [(280 - 821) / 821] x 100
Subtract the new number by the original number
280 - 821 = -541
-541 ÷ 821 = -0.658952496954933
-0.658952496954933 x 100 = -65.9%