59.31% is the change from 521 to 830
Calculation steps:
[( 830 - 521 ) ÷ 521] x 100 = 59.31%
Formula
Percentage change = [(830 - 521) / 521] x 100
Subtract the new number by the original number
830 - 521 = 309
309 ÷ 521 = 0.5930902111324377
0.5930902111324377 x 100 = 59.31%