-8.7% is the change from 839 to 766
Calculation steps:
[( 766 - 839 ) ÷ 839] x 100 = -8.7%
Formula
Percentage change = [(766 - 839) / 839] x 100
Subtract the new number by the original number
766 - 839 = -73
-73 ÷ 839 = -0.08700834326579261
-0.08700834326579261 x 100 = -8.7%