-5.43% is the change from 921 to 871
Calculation steps:
[( 871 - 921 ) ÷ 921] x 100 = -5.43%
Formula
Percentage change = [(871 - 921) / 921] x 100
Subtract the new number by the original number
871 - 921 = -50
-50 ÷ 921 = -0.05428881650380022
-0.05428881650380022 x 100 = -5.43%