63.94% is the change from 391 to 641
Calculation steps:
[( 641 - 391 ) ÷ 391] x 100 = 63.94%
Formula
Percentage change = [(641 - 391) / 391] x 100
Subtract the new number by the original number
641 - 391 = 250
250 ÷ 391 = 0.639386189258312
0.639386189258312 x 100 = 63.94%