-30.86% is the change from 81 to 56
Calculation steps:
[( 56 - 81 ) ÷ 81] x 100 = -30.86%
Formula
Percentage change = [(56 - 81) / 81] x 100
Subtract the new number by the original number
56 - 81 = -25
-25 ÷ 81 = -0.30864197530864196
-0.30864197530864196 x 100 = -30.86%