-90.82% is the change from 850 to 78
Calculation steps:
[( 78 - 850 ) ÷ 850] x 100 = -90.82%
Formula
Percentage change = [(78 - 850) / 850] x 100
Subtract the new number by the original number
78 - 850 = -772
-772 ÷ 850 = -0.908235294117647
-0.908235294117647 x 100 = -90.82%