0.81% is the change from 991 to 999
Calculation steps:
[( 999 - 991 ) ÷ 991] x 100 = 0.81%
Formula
Percentage change = [(999 - 991) / 991] x 100
Subtract the new number by the original number
999 - 991 = 8
8 ÷ 991 = 0.008072653884964682
0.008072653884964682 x 100 = 0.81%