-45.18% is the change from 166 to 91
Calculation steps:
[( 91 - 166 ) ÷ 166] x 100 = -45.18%
Formula
Percentage change = [(91 - 166) / 166] x 100
Subtract the new number by the original number
91 - 166 = -75
-75 ÷ 166 = -0.45180722891566266
-0.45180722891566266 x 100 = -45.18%