-90% is the change from 860 to 86
Calculation steps:
[( 86 - 860 ) ÷ 860] x 100 = -90%
Formula
Percentage change = [(86 - 860) / 860] x 100
Subtract the new number by the original number
86 - 860 = -774
-774 ÷ 860 = -0.9
-0.9 x 100 = -90%
Example