68.85% is the change from 305 to 515
Calculation steps:
[( 515 - 305 ) ÷ 305] x 100 = 68.85%
Formula
Percentage change = [(515 - 305) / 305] x 100
Subtract the new number by the original number
515 - 305 = 210
210 ÷ 305 = 0.6885245901639344
0.6885245901639344 x 100 = 68.85%