69.82% is the change from 391 to 664
Calculation steps:
[( 664 - 391 ) ÷ 391] x 100 = 69.82%
Formula
Percentage change = [(664 - 391) / 391] x 100
Subtract the new number by the original number
664 - 391 = 273
273 ÷ 391 = 0.6982097186700768
0.6982097186700768 x 100 = 69.82%