78.69% is the change from 521 to 931
Calculation steps:
[( 931 - 521 ) ÷ 521] x 100 = 78.69%
Formula
Percentage change = [(931 - 521) / 521] x 100
Subtract the new number by the original number
931 - 521 = 410
410 ÷ 521 = 0.7869481765834933
0.7869481765834933 x 100 = 78.69%