-30.72% is the change from 166 to 115
Calculation steps:
[( 115 - 166 ) ÷ 166] x 100 = -30.72%
Formula
Percentage change = [(115 - 166) / 166] x 100
Subtract the new number by the original number
115 - 166 = -51
-51 ÷ 166 = -0.3072289156626506
-0.3072289156626506 x 100 = -30.72%