-86.96% is the change from 690 to 90
Calculation steps:
[( 90 - 690 ) ÷ 690] x 100 = -86.96%
Formula
Percentage change = [(90 - 690) / 690] x 100
Subtract the new number by the original number
90 - 690 = -600
-600 ÷ 690 = -0.8695652173913043
-0.8695652173913043 x 100 = -86.96%