-75.31% is the change from 81 to 20
Calculation steps:
[( 20 - 81 ) ÷ 81] x 100 = -75.31%
Formula
Percentage change = [(20 - 81) / 81] x 100
Subtract the new number by the original number
20 - 81 = -61
-61 ÷ 81 = -0.7530864197530864
-0.7530864197530864 x 100 = -75.31%