-13.64% is the change from 638 to 551
Calculation steps:
[( 551 - 638 ) ÷ 638] x 100 = -13.64%
Formula
Percentage change = [(551 - 638) / 638] x 100
Subtract the new number by the original number
551 - 638 = -87
-87 ÷ 638 = -0.13636363636363635
-0.13636363636363635 x 100 = -13.64%