-81.79% is the change from 851 to 155
Calculation steps:
[( 155 - 851 ) ÷ 851] x 100 = -81.79%
Formula
Percentage change = [(155 - 851) / 851] x 100
Subtract the new number by the original number
155 - 851 = -696
-696 ÷ 851 = -0.81786133960047
-0.81786133960047 x 100 = -81.79%