-86.59% is the change from 634 to 85
Calculation steps:
[( 85 - 634 ) ÷ 634] x 100 = -86.59%
Formula
Percentage change = [(85 - 634) / 634] x 100
Subtract the new number by the original number
85 - 634 = -549
-549 ÷ 634 = -0.8659305993690851
-0.8659305993690851 x 100 = -86.59%