-1.83% is the change from 821 to 806
Calculation steps:
[( 806 - 821 ) ÷ 821] x 100 = -1.83%
Formula
Percentage change = [(806 - 821) / 821] x 100
Subtract the new number by the original number
806 - 821 = -15
-15 ÷ 821 = -0.018270401948842874
-0.018270401948842874 x 100 = -1.83%