-50.86% is the change from 812 to 399
Calculation steps:
[( 399 - 812 ) ÷ 812] x 100 = -50.86%
Formula
Percentage change = [(399 - 812) / 812] x 100
Subtract the new number by the original number
399 - 812 = -413
-413 ÷ 812 = -0.5086206896551724
-0.5086206896551724 x 100 = -50.86%