20.59% is the change from 510 to 615
Calculation steps:
[( 615 - 510 ) ÷ 510] x 100 = 20.59%
Formula
Percentage change = [(615 - 510) / 510] x 100
Subtract the new number by the original number
615 - 510 = 105
105 ÷ 510 = 0.20588235294117646
0.20588235294117646 x 100 = 20.59%