-1.25% is the change from 638 to 630
Calculation steps:
[( 630 - 638 ) ÷ 638] x 100 = -1.25%
Formula
Percentage change = [(630 - 638) / 638] x 100
Subtract the new number by the original number
630 - 638 = -8
-8 ÷ 638 = -0.012539184952978056
-0.012539184952978056 x 100 = -1.25%