-9.88% is the change from 81 to 73
Calculation steps:
[( 73 - 81 ) ÷ 81] x 100 = -9.88%
Formula
Percentage change = [(73 - 81) / 81] x 100
Subtract the new number by the original number
73 - 81 = -8
-8 ÷ 81 = -0.09876543209876543
-0.09876543209876543 x 100 = -9.88%