-10.57% is the change from 870 to 778
Calculation steps:
[( 778 - 870 ) ÷ 870] x 100 = -10.57%
Formula
Percentage change = [(778 - 870) / 870] x 100
Subtract the new number by the original number
778 - 870 = -92
-92 ÷ 870 = -0.10574712643678161
-0.10574712643678161 x 100 = -10.57%