-19.28% is the change from 638 to 515
Calculation steps:
[( 515 - 638 ) ÷ 638] x 100 = -19.28%
Formula
Percentage change = [(515 - 638) / 638] x 100
Subtract the new number by the original number
515 - 638 = -123
-123 ÷ 638 = -0.19278996865203762
-0.19278996865203762 x 100 = -19.28%