-86.29% is the change from 591 to 81
Calculation steps:
[( 81 - 591 ) ÷ 591] x 100 = -86.29%
Formula
Percentage change = [(81 - 591) / 591] x 100
Subtract the new number by the original number
81 - 591 = -510
-510 ÷ 591 = -0.8629441624365483
-0.8629441624365483 x 100 = -86.29%