-81.41% is the change from 850 to 158
Calculation steps:
[( 158 - 850 ) ÷ 850] x 100 = -81.41%
Formula
Percentage change = [(158 - 850) / 850] x 100
Subtract the new number by the original number
158 - 850 = -692
-692 ÷ 850 = -0.8141176470588235
-0.8141176470588235 x 100 = -81.41%