-50.91% is the change from 165 to 81
Calculation steps:
[( 81 - 165 ) ÷ 165] x 100 = -50.91%
Formula
Percentage change = [(81 - 165) / 165] x 100
Subtract the new number by the original number
81 - 165 = -84
-84 ÷ 165 = -0.509090909090909
-0.509090909090909 x 100 = -50.91%