-86.74% is the change from 641 to 85
Calculation steps:
[( 85 - 641 ) ÷ 641] x 100 = -86.74%
Formula
Percentage change = [(85 - 641) / 641] x 100
Subtract the new number by the original number
85 - 641 = -556
-556 ÷ 641 = -0.8673946957878315
-0.8673946957878315 x 100 = -86.74%