2.41% is the change from 870 to 891
Calculation steps:
[( 891 - 870 ) ÷ 870] x 100 = 2.41%
Formula
Percentage change = [(891 - 870) / 870] x 100
Subtract the new number by the original number
891 - 870 = 21
21 ÷ 870 = 0.02413793103448276
0.02413793103448276 x 100 = 2.41%