3.65% is the change from 821 to 851
Calculation steps:
[( 851 - 821 ) ÷ 821] x 100 = 3.65%
Formula
Percentage change = [(851 - 821) / 821] x 100
Subtract the new number by the original number
851 - 821 = 30
30 ÷ 821 = 0.03654080389768575
0.03654080389768575 x 100 = 3.65%