-49.4% is the change from 836 to 423
Calculation steps:
[( 423 - 836 ) ÷ 836] x 100 = -49.4%
Formula
Percentage change = [(423 - 836) / 836] x 100
Subtract the new number by the original number
423 - 836 = -413
-413 ÷ 836 = -0.49401913875598086
-0.49401913875598086 x 100 = -49.4%