61.4% is the change from 399 to 644
Calculation steps:
[( 644 - 399 ) ÷ 399] x 100 = 61.4%
Formula
Percentage change = [(644 - 399) / 399] x 100
Subtract the new number by the original number
644 - 399 = 245
245 ÷ 399 = 0.6140350877192983
0.6140350877192983 x 100 = 61.4%