-90.12% is the change from 81 to 8
Calculation steps:
[( 8 - 81 ) ÷ 81] x 100 = -90.12%
Formula
Percentage change = [(8 - 81) / 81] x 100
Subtract the new number by the original number
8 - 81 = -73
-73 ÷ 81 = -0.9012345679012346
-0.9012345679012346 x 100 = -90.12%