-86.76% is the change from 680 to 90
Calculation steps:
[( 90 - 680 ) ÷ 680] x 100 = -86.76%
Formula
Percentage change = [(90 - 680) / 680] x 100
Subtract the new number by the original number
90 - 680 = -590
-590 ÷ 680 = -0.8676470588235294
-0.8676470588235294 x 100 = -86.76%