12.27% is the change from 815 to 915
Calculation steps:
[( 915 - 815 ) ÷ 815] x 100 = 12.27%
Formula
Percentage change = [(915 - 815) / 815] x 100
Subtract the new number by the original number
915 - 815 = 100
100 ÷ 815 = 0.12269938650306748
0.12269938650306748 x 100 = 12.27%