87.5% is the change from 8 to 15
Calculation steps:
[( 15 - 8 ) ÷ 8] x 100 = 87.5%
Formula
Percentage change = [(15 - 8) / 8] x 100
Subtract the new number by the original number
15 - 8 = 7
7 ÷ 8 = 0.875
0.875 x 100 = 87.5%
Example