-97.7% is the change from 305 to 7
Calculation steps:
[( 7 - 305 ) ÷ 305] x 100 = -97.7%
Formula
Percentage change = [(7 - 305) / 305] x 100
Subtract the new number by the original number
7 - 305 = -298
-298 ÷ 305 = -0.9770491803278688
-0.9770491803278688 x 100 = -97.7%