-36.4% is the change from 500 to 318
Calculation steps:
[( 318 - 500 ) ÷ 500] x 100 = -36.4%
Formula
Percentage change = [(318 - 500) / 500] x 100
Subtract the new number by the original number
318 - 500 = -182
-182 ÷ 500 = -0.364
-0.364 x 100 = -36.4%