31.71% is the change from 615 to 810
Calculation steps:
[( 810 - 615 ) ÷ 615] x 100 = 31.71%
Formula
Percentage change = [(810 - 615) / 615] x 100
Subtract the new number by the original number
810 - 615 = 195
195 ÷ 615 = 0.3170731707317073
0.3170731707317073 x 100 = 31.71%