68.17% is the change from 399 to 671
Calculation steps:
[( 671 - 399 ) ÷ 399] x 100 = 68.17%
Formula
Percentage change = [(671 - 399) / 399] x 100
Subtract the new number by the original number
671 - 399 = 272
272 ÷ 399 = 0.681704260651629
0.681704260651629 x 100 = 68.17%