-20.69% is the change from 836 to 663
Calculation steps:
[( 663 - 836 ) ÷ 836] x 100 = -20.69%
Formula
Percentage change = [(663 - 836) / 836] x 100
Subtract the new number by the original number
663 - 836 = -173
-173 ÷ 836 = -0.2069377990430622
-0.2069377990430622 x 100 = -20.69%