-99.06% is the change from 850 to 8
Calculation steps:
[( 8 - 850 ) ÷ 850] x 100 = -99.06%
Formula
Percentage change = [(8 - 850) / 850] x 100
Subtract the new number by the original number
8 - 850 = -842
-842 ÷ 850 = -0.9905882352941177
-0.9905882352941177 x 100 = -99.06%