-87.52% is the change from 649 to 81
Calculation steps:
[( 81 - 649 ) ÷ 649] x 100 = -87.52%
Formula
Percentage change = [(81 - 649) / 649] x 100
Subtract the new number by the original number
81 - 649 = -568
-568 ÷ 649 = -0.8751926040061633
-0.8751926040061633 x 100 = -87.52%