-84.02% is the change from 507 to 81
Calculation steps:
[( 81 - 507 ) ÷ 507] x 100 = -84.02%
Formula
Percentage change = [(81 - 507) / 507] x 100
Subtract the new number by the original number
81 - 507 = -426
-426 ÷ 507 = -0.8402366863905325
-0.8402366863905325 x 100 = -84.02%