-9.52% is the change from 851 to 770
Calculation steps:
[( 770 - 851 ) ÷ 851] x 100 = -9.52%
Formula
Percentage change = [(770 - 851) / 851] x 100
Subtract the new number by the original number
770 - 851 = -81
-81 ÷ 851 = -0.09518213866039953
-0.09518213866039953 x 100 = -9.52%