-87.56% is the change from 651 to 81
Calculation steps:
[( 81 - 651 ) ÷ 651] x 100 = -87.56%
Formula
Percentage change = [(81 - 651) / 651] x 100
Subtract the new number by the original number
81 - 651 = -570
-570 ÷ 651 = -0.8755760368663594
-0.8755760368663594 x 100 = -87.56%