-49.4% is the change from 166 to 84
Calculation steps:
[( 84 - 166 ) ÷ 166] x 100 = -49.4%
Formula
Percentage change = [(84 - 166) / 166] x 100
Subtract the new number by the original number
84 - 166 = -82
-82 ÷ 166 = -0.4939759036144578
-0.4939759036144578 x 100 = -49.4%