-50.31% is the change from 320 to 159
Calculation steps:
[( 159 - 320 ) ÷ 320] x 100 = -50.31%
Formula
Percentage change = [(159 - 320) / 320] x 100
Subtract the new number by the original number
159 - 320 = -161
-161 ÷ 320 = -0.503125
-0.503125 x 100 = -50.31%