-90.4% is the change from 323 to 31
Calculation steps:
[( 31 - 323 ) ÷ 323] x 100 = -90.4%
Formula
Percentage change = [(31 - 323) / 323] x 100
Subtract the new number by the original number
31 - 323 = -292
-292 ÷ 323 = -0.9040247678018576
-0.9040247678018576 x 100 = -90.4%