-50.79% is the change from 821 to 404
Calculation steps:
[( 404 - 821 ) ÷ 821] x 100 = -50.79%
Formula
Percentage change = [(404 - 821) / 821] x 100
Subtract the new number by the original number
404 - 821 = -417
-417 ÷ 821 = -0.5079171741778319
-0.5079171741778319 x 100 = -50.79%