-81.82% is the change from 165 to 30
Calculation steps:
[( 30 - 165 ) ÷ 165] x 100 = -81.82%
Formula
Percentage change = [(30 - 165) / 165] x 100
Subtract the new number by the original number
30 - 165 = -135
-135 ÷ 165 = -0.8181818181818182
-0.8181818181818182 x 100 = -81.82%