-50% is the change from 328 to 164
Calculation steps:
[( 164 - 328 ) ÷ 328] x 100 = -50%
Formula
Percentage change = [(164 - 328) / 328] x 100
Subtract the new number by the original number
164 - 328 = -164
-164 ÷ 328 = -0.5
-0.5 x 100 = -50%
Example