-4.28% is the change from 491 to 470
Calculation steps:
[( 470 - 491 ) ÷ 491] x 100 = -4.28%
Formula
Percentage change = [(470 - 491) / 491] x 100
Subtract the new number by the original number
470 - 491 = -21
-21 ÷ 491 = -0.04276985743380855
-0.04276985743380855 x 100 = -4.28%