12.18% is the change from 821 to 921
Calculation steps:
[( 921 - 821 ) ÷ 821] x 100 = 12.18%
Formula
Percentage change = [(921 - 821) / 821] x 100
Subtract the new number by the original number
921 - 821 = 100
100 ÷ 821 = 0.1218026796589525
0.1218026796589525 x 100 = 12.18%