70.33% is the change from 391 to 666
Calculation steps:
[( 666 - 391 ) ÷ 391] x 100 = 70.33%
Formula
Percentage change = [(666 - 391) / 391] x 100
Subtract the new number by the original number
666 - 391 = 275
275 ÷ 391 = 0.7033248081841432
0.7033248081841432 x 100 = 70.33%