-50.31% is the change from 163 to 81
Calculation steps:
[( 81 - 163 ) ÷ 163] x 100 = -50.31%
Formula
Percentage change = [(81 - 163) / 163] x 100
Subtract the new number by the original number
81 - 163 = -82
-82 ÷ 163 = -0.5030674846625767
-0.5030674846625767 x 100 = -50.31%