61.9% is the change from 399 to 646
Calculation steps:
[( 646 - 399 ) ÷ 399] x 100 = 61.9%
Formula
Percentage change = [(646 - 399) / 399] x 100
Subtract the new number by the original number
646 - 399 = 247
247 ÷ 399 = 0.6190476190476191
0.6190476190476191 x 100 = 61.9%