-2.03% is the change from 640 to 627
Calculation steps:
[( 627 - 640 ) ÷ 640] x 100 = -2.03%
Formula
Percentage change = [(627 - 640) / 640] x 100
Subtract the new number by the original number
627 - 640 = -13
-13 ÷ 640 = -0.0203125
-0.0203125 x 100 = -2.03%