100.63% is the change from 319 to 640
Calculation steps:
[( 640 - 319 ) ÷ 319] x 100 = 100.63%
Formula
Percentage change = [(640 - 319) / 319] x 100
Subtract the new number by the original number
640 - 319 = 321
321 ÷ 319 = 1.006269592476489
1.006269592476489 x 100 = 100.63%