-1.71% is the change from 879 to 864
Calculation steps:
[( 864 - 879 ) ÷ 879] x 100 = -1.71%
Formula
Percentage change = [(864 - 879) / 879] x 100
Subtract the new number by the original number
864 - 879 = -15
-15 ÷ 879 = -0.017064846416382253
-0.017064846416382253 x 100 = -1.71%