-49.69% is the change from 161 to 81
Calculation steps:
[( 81 - 161 ) ÷ 161] x 100 = -49.69%
Formula
Percentage change = [(81 - 161) / 161] x 100
Subtract the new number by the original number
81 - 161 = -80
-80 ÷ 161 = -0.4968944099378882
-0.4968944099378882 x 100 = -49.69%