-52.99% is the change from 670 to 315
Calculation steps:
[( 315 - 670 ) ÷ 670] x 100 = -52.99%
Formula
Percentage change = [(315 - 670) / 670] x 100
Subtract the new number by the original number
315 - 670 = -355
-355 ÷ 670 = -0.5298507462686567
-0.5298507462686567 x 100 = -52.99%