-97.9% is the change from 856 to 18
Calculation steps:
[( 18 - 856 ) ÷ 856] x 100 = -97.9%
Formula
Percentage change = [(18 - 856) / 856] x 100
Subtract the new number by the original number
18 - 856 = -838
-838 ÷ 856 = -0.9789719626168224
-0.9789719626168224 x 100 = -97.9%