8.31% is the change from 915 to 991
Calculation steps:
[( 991 - 915 ) ÷ 915] x 100 = 8.31%
Formula
Percentage change = [(991 - 915) / 915] x 100
Subtract the new number by the original number
991 - 915 = 76
76 ÷ 915 = 0.08306010928961749
0.08306010928961749 x 100 = 8.31%