65.9% is the change from 390 to 647
Calculation steps:
[( 647 - 390 ) ÷ 390] x 100 = 65.9%
Formula
Percentage change = [(647 - 390) / 390] x 100
Subtract the new number by the original number
647 - 390 = 257
257 ÷ 390 = 0.658974358974359
0.658974358974359 x 100 = 65.9%