-83.33% is the change from 180 to 30
Calculation steps:
[( 30 - 180 ) ÷ 180] x 100 = -83.33%
Formula
Percentage change = [(30 - 180) / 180] x 100
Subtract the new number by the original number
30 - 180 = -150
-150 ÷ 180 = -0.8333333333333334
-0.8333333333333334 x 100 = -83.33%