-87.24% is the change from 666 to 85
Calculation steps:
[( 85 - 666 ) ÷ 666] x 100 = -87.24%
Formula
Percentage change = [(85 - 666) / 666] x 100
Subtract the new number by the original number
85 - 666 = -581
-581 ÷ 666 = -0.8723723723723724
-0.8723723723723724 x 100 = -87.24%