-90.67% is the change from 857 to 80
Calculation steps:
[( 80 - 857 ) ÷ 857] x 100 = -90.67%
Formula
Percentage change = [(80 - 857) / 857] x 100
Subtract the new number by the original number
80 - 857 = -777
-777 ÷ 857 = -0.9066511085180864
-0.9066511085180864 x 100 = -90.67%