-50.74% is the change from 678 to 334
Calculation steps:
[( 334 - 678 ) ÷ 678] x 100 = -50.74%
Formula
Percentage change = [(334 - 678) / 678] x 100
Subtract the new number by the original number
334 - 678 = -344
-344 ÷ 678 = -0.5073746312684366
-0.5073746312684366 x 100 = -50.74%