-91.35% is the change from 936 to 81
Calculation steps:
[( 81 - 936 ) ÷ 936] x 100 = -91.35%
Formula
Percentage change = [(81 - 936) / 936] x 100
Subtract the new number by the original number
81 - 936 = -855
-855 ÷ 936 = -0.9134615384615384
-0.9134615384615384 x 100 = -91.35%