-97.78% is the change from 315 to 7
Calculation steps:
[( 7 - 315 ) ÷ 315] x 100 = -97.78%
Formula
Percentage change = [(7 - 315) / 315] x 100
Subtract the new number by the original number
7 - 315 = -308
-308 ÷ 315 = -0.9777777777777777
-0.9777777777777777 x 100 = -97.78%