-29.82% is the change from 171 to 120
Calculation steps:
[( 120 - 171 ) ÷ 171] x 100 = -29.82%
Formula
Percentage change = [(120 - 171) / 171] x 100
Subtract the new number by the original number
120 - 171 = -51
-51 ÷ 171 = -0.2982456140350877
-0.2982456140350877 x 100 = -29.82%