-87.5% is the change from 720 to 90
Calculation steps:
[( 90 - 720 ) ÷ 720] x 100 = -87.5%
Formula
Percentage change = [(90 - 720) / 720] x 100
Subtract the new number by the original number
90 - 720 = -630
-630 ÷ 720 = -0.875
-0.875 x 100 = -87.5%
Example