-96.5% is the change from 857 to 30
Calculation steps:
[( 30 - 857 ) ÷ 857] x 100 = -96.5%
Formula
Percentage change = [(30 - 857) / 857] x 100
Subtract the new number by the original number
30 - 857 = -827
-827 ÷ 857 = -0.9649941656942824
-0.9649941656942824 x 100 = -96.5%