-39.29% is the change from 504 to 306
Calculation steps:
[( 306 - 504 ) ÷ 504] x 100 = -39.29%
Formula
Percentage change = [(306 - 504) / 504] x 100
Subtract the new number by the original number
306 - 504 = -198
-198 ÷ 504 = -0.39285714285714285
-0.39285714285714285 x 100 = -39.29%