-73.7% is the change from 308 to 81
Calculation steps:
[( 81 - 308 ) ÷ 308] x 100 = -73.7%
Formula
Percentage change = [(81 - 308) / 308] x 100
Subtract the new number by the original number
81 - 308 = -227
-227 ÷ 308 = -0.737012987012987
-0.737012987012987 x 100 = -73.7%