-99.18% is the change from 850 to 7
Calculation steps:
[( 7 - 850 ) ÷ 850] x 100 = -99.18%
Formula
Percentage change = [(7 - 850) / 850] x 100
Subtract the new number by the original number
7 - 850 = -843
-843 ÷ 850 = -0.991764705882353
-0.991764705882353 x 100 = -99.18%