-4.02% is the change from 646 to 620
Calculation steps:
[( 620 - 646 ) ÷ 646] x 100 = -4.02%
Formula
Percentage change = [(620 - 646) / 646] x 100
Subtract the new number by the original number
620 - 646 = -26
-26 ÷ 646 = -0.04024767801857585
-0.04024767801857585 x 100 = -4.02%