-3.26% is the change from 921 to 891
Calculation steps:
[( 891 - 921 ) ÷ 921] x 100 = -3.26%
Formula
Percentage change = [(891 - 921) / 921] x 100
Subtract the new number by the original number
891 - 921 = -30
-30 ÷ 921 = -0.03257328990228013
-0.03257328990228013 x 100 = -3.26%