13.79% is the change from 870 to 990
Calculation steps:
[( 990 - 870 ) ÷ 870] x 100 = 13.79%
Formula
Percentage change = [(990 - 870) / 870] x 100
Subtract the new number by the original number
990 - 870 = 120
120 ÷ 870 = 0.13793103448275862
0.13793103448275862 x 100 = 13.79%