-98.59% is the change from 850 to 12
Calculation steps:
[( 12 - 850 ) ÷ 850] x 100 = -98.59%
Formula
Percentage change = [(12 - 850) / 850] x 100
Subtract the new number by the original number
12 - 850 = -838
-838 ÷ 850 = -0.9858823529411764
-0.9858823529411764 x 100 = -98.59%