-3.41% is the change from 646 to 624
Calculation steps:
[( 624 - 646 ) ÷ 646] x 100 = -3.41%
Formula
Percentage change = [(624 - 646) / 646] x 100
Subtract the new number by the original number
624 - 646 = -22
-22 ÷ 646 = -0.034055727554179564
-0.034055727554179564 x 100 = -3.41%