99.23% is the change from 390 to 777
Calculation steps:
[( 777 - 390 ) ÷ 390] x 100 = 99.23%
Formula
Percentage change = [(777 - 390) / 390] x 100
Subtract the new number by the original number
777 - 390 = 387
387 ÷ 390 = 0.9923076923076923
0.9923076923076923 x 100 = 99.23%