-50% is the change from 332 to 166
Calculation steps:
[( 166 - 332 ) ÷ 332] x 100 = -50%
Formula
Percentage change = [(166 - 332) / 332] x 100
Subtract the new number by the original number
166 - 332 = -166
-166 ÷ 332 = -0.5
-0.5 x 100 = -50%
Example