-89.64% is the change from 878 to 91
Calculation steps:
[( 91 - 878 ) ÷ 878] x 100 = -89.64%
Formula
Percentage change = [(91 - 878) / 878] x 100
Subtract the new number by the original number
91 - 878 = -787
-787 ÷ 878 = -0.8963553530751709
-0.8963553530751709 x 100 = -89.64%