-50.93% is the change from 648 to 318
Calculation steps:
[( 318 - 648 ) ÷ 648] x 100 = -50.93%
Formula
Percentage change = [(318 - 648) / 648] x 100
Subtract the new number by the original number
318 - 648 = -330
-330 ÷ 648 = -0.5092592592592593
-0.5092592592592593 x 100 = -50.93%