1.1% is the change from 821 to 830
Calculation steps:
[( 830 - 821 ) ÷ 821] x 100 = 1.1%
Formula
Percentage change = [(830 - 821) / 821] x 100
Subtract the new number by the original number
830 - 821 = 9
9 ÷ 821 = 0.010962241169305725
0.010962241169305725 x 100 = 1.1%