-89.76% is the change from 879 to 90
Calculation steps:
[( 90 - 879 ) ÷ 879] x 100 = -89.76%
Formula
Percentage change = [(90 - 879) / 879] x 100
Subtract the new number by the original number
90 - 879 = -789
-789 ÷ 879 = -0.8976109215017065
-0.8976109215017065 x 100 = -89.76%