3.28% is the change from 305 to 315
Calculation steps:
[( 315 - 305 ) ÷ 305] x 100 = 3.28%
Formula
Percentage change = [(315 - 305) / 305] x 100
Subtract the new number by the original number
315 - 305 = 10
10 ÷ 305 = 0.03278688524590164
0.03278688524590164 x 100 = 3.28%