-0.32% is the change from 623 to 621
Calculation steps:
[( 621 - 623 ) ÷ 623] x 100 = -0.32%
Formula
Percentage change = [(621 - 623) / 623] x 100
Subtract the new number by the original number
621 - 623 = -2
-2 ÷ 623 = -0.0032102728731942215
-0.0032102728731942215 x 100 = -0.32%