-20.4% is the change from 843 to 671
Calculation steps:
[( 671 - 843 ) ÷ 843] x 100 = -20.4%
Formula
Percentage change = [(671 - 843) / 843] x 100
Subtract the new number by the original number
671 - 843 = -172
-172 ÷ 843 = -0.2040332147093713
-0.2040332147093713 x 100 = -20.4%