-4.02% is the change from 647 to 621
Calculation steps:
[( 621 - 647 ) ÷ 647] x 100 = -4.02%
Formula
Percentage change = [(621 - 647) / 647] x 100
Subtract the new number by the original number
621 - 647 = -26
-26 ÷ 647 = -0.0401854714064915
-0.0401854714064915 x 100 = -4.02%