-12.4% is the change from 879 to 770
Calculation steps:
[( 770 - 879 ) ÷ 879] x 100 = -12.4%
Formula
Percentage change = [(770 - 879) / 879] x 100
Subtract the new number by the original number
770 - 879 = -109
-109 ÷ 879 = -0.12400455062571103
-0.12400455062571103 x 100 = -12.4%