67.92% is the change from 399 to 670
Calculation steps:
[( 670 - 399 ) ÷ 399] x 100 = 67.92%
Formula
Percentage change = [(670 - 399) / 399] x 100
Subtract the new number by the original number
670 - 399 = 271
271 ÷ 399 = 0.6791979949874687
0.6791979949874687 x 100 = 67.92%