-87.29% is the change from 669 to 85
Calculation steps:
[( 85 - 669 ) ÷ 669] x 100 = -87.29%
Formula
Percentage change = [(85 - 669) / 669] x 100
Subtract the new number by the original number
85 - 669 = -584
-584 ÷ 669 = -0.8729446935724963
-0.8729446935724963 x 100 = -87.29%