8.46% is the change from 390 to 423
Calculation steps:
[( 423 - 390 ) ÷ 390] x 100 = 8.46%
Formula
Percentage change = [(423 - 390) / 390] x 100
Subtract the new number by the original number
423 - 390 = 33
33 ÷ 390 = 0.08461538461538462
0.08461538461538462 x 100 = 8.46%