-50.37% is the change from 804 to 399
Calculation steps:
[( 399 - 804 ) ÷ 804] x 100 = -50.37%
Formula
Percentage change = [(399 - 804) / 804] x 100
Subtract the new number by the original number
399 - 804 = -405
-405 ÷ 804 = -0.503731343283582
-0.503731343283582 x 100 = -50.37%