-87.65% is the change from 81 to 10
Calculation steps:
[( 10 - 81 ) ÷ 81] x 100 = -87.65%
Formula
Percentage change = [(10 - 81) / 81] x 100
Subtract the new number by the original number
10 - 81 = -71
-71 ÷ 81 = -0.8765432098765432
-0.8765432098765432 x 100 = -87.65%