34.9% is the change from 510 to 688
Calculation steps:
[( 688 - 510 ) ÷ 510] x 100 = 34.9%
Formula
Percentage change = [(688 - 510) / 510] x 100
Subtract the new number by the original number
688 - 510 = 178
178 ÷ 510 = 0.34901960784313724
0.34901960784313724 x 100 = 34.9%