-5.15% is the change from 971 to 921
Calculation steps:
[( 921 - 971 ) ÷ 971] x 100 = -5.15%
Formula
Percentage change = [(921 - 971) / 971] x 100
Subtract the new number by the original number
921 - 971 = -50
-50 ÷ 971 = -0.05149330587023687
-0.05149330587023687 x 100 = -5.15%