-71.07% is the change from 280 to 81
Calculation steps:
[( 81 - 280 ) ÷ 280] x 100 = -71.07%
Formula
Percentage change = [(81 - 280) / 280] x 100
Subtract the new number by the original number
81 - 280 = -199
-199 ÷ 280 = -0.7107142857142857
-0.7107142857142857 x 100 = -71.07%