20.12% is the change from 512 to 615
Calculation steps:
[( 615 - 512 ) ÷ 512] x 100 = 20.12%
Formula
Percentage change = [(615 - 512) / 512] x 100
Subtract the new number by the original number
615 - 512 = 103
103 ÷ 512 = 0.201171875
0.201171875 x 100 = 20.12%