-20.9% is the change from 804 to 636
Calculation steps:
[( 636 - 804 ) ÷ 804] x 100 = -20.9%
Formula
Percentage change = [(636 - 804) / 804] x 100
Subtract the new number by the original number
636 - 804 = -168
-168 ÷ 804 = -0.208955223880597
-0.208955223880597 x 100 = -20.9%