-11.95% is the change from 870 to 766
Calculation steps:
[( 766 - 870 ) ÷ 870] x 100 = -11.95%
Formula
Percentage change = [(766 - 870) / 870] x 100
Subtract the new number by the original number
766 - 870 = -104
-104 ÷ 870 = -0.11954022988505747
-0.11954022988505747 x 100 = -11.95%