-83.13% is the change from 166 to 28
Calculation steps:
[( 28 - 166 ) ÷ 166] x 100 = -83.13%
Formula
Percentage change = [(28 - 166) / 166] x 100
Subtract the new number by the original number
28 - 166 = -138
-138 ÷ 166 = -0.8313253012048193
-0.8313253012048193 x 100 = -83.13%