-20.12% is the change from 850 to 679
Calculation steps:
[( 679 - 850 ) ÷ 850] x 100 = -20.12%
Formula
Percentage change = [(679 - 850) / 850] x 100
Subtract the new number by the original number
679 - 850 = -171
-171 ÷ 850 = -0.2011764705882353
-0.2011764705882353 x 100 = -20.12%