53.38% is the change from 399 to 612
Calculation steps:
[( 612 - 399 ) ÷ 399] x 100 = 53.38%
Formula
Percentage change = [(612 - 399) / 399] x 100
Subtract the new number by the original number
612 - 399 = 213
213 ÷ 399 = 0.5338345864661654
0.5338345864661654 x 100 = 53.38%