66.03% is the change from 521 to 865
Calculation steps:
[( 865 - 521 ) ÷ 521] x 100 = 66.03%
Formula
Percentage change = [(865 - 521) / 521] x 100
Subtract the new number by the original number
865 - 521 = 344
344 ÷ 521 = 0.6602687140115163
0.6602687140115163 x 100 = 66.03%