-0.43% is the change from 921 to 917
Calculation steps:
[( 917 - 921 ) ÷ 921] x 100 = -0.43%
Formula
Percentage change = [(917 - 921) / 921] x 100
Subtract the new number by the original number
917 - 921 = -4
-4 ÷ 921 = -0.004343105320304018
-0.004343105320304018 x 100 = -0.43%