-90.04% is the change from 813 to 81
Calculation steps:
[( 81 - 813 ) ÷ 813] x 100 = -90.04%
Formula
Percentage change = [(81 - 813) / 813] x 100
Subtract the new number by the original number
81 - 813 = -732
-732 ÷ 813 = -0.9003690036900369
-0.9003690036900369 x 100 = -90.04%