-50% is the change from 306 to 153
Calculation steps:
[( 153 - 306 ) ÷ 306] x 100 = -50%
Formula
Percentage change = [(153 - 306) / 306] x 100
Subtract the new number by the original number
153 - 306 = -153
-153 ÷ 306 = -0.5
-0.5 x 100 = -50%
Example