-87.95% is the change from 672 to 81
Calculation steps:
[( 81 - 672 ) ÷ 672] x 100 = -87.95%
Formula
Percentage change = [(81 - 672) / 672] x 100
Subtract the new number by the original number
81 - 672 = -591
-591 ÷ 672 = -0.8794642857142857
-0.8794642857142857 x 100 = -87.95%