67.21% is the change from 305 to 510
Calculation steps:
[( 510 - 305 ) ÷ 305] x 100 = 67.21%
Formula
Percentage change = [(510 - 305) / 305] x 100
Subtract the new number by the original number
510 - 305 = 205
205 ÷ 305 = 0.6721311475409836
0.6721311475409836 x 100 = 67.21%