-52.9% is the change from 828 to 390
Calculation steps:
[( 390 - 828 ) ÷ 828] x 100 = -52.9%
Formula
Percentage change = [(390 - 828) / 828] x 100
Subtract the new number by the original number
390 - 828 = -438
-438 ÷ 828 = -0.5289855072463768
-0.5289855072463768 x 100 = -52.9%