30.71% is the change from 521 to 681
Calculation steps:
[( 681 - 521 ) ÷ 521] x 100 = 30.71%
Formula
Percentage change = [(681 - 521) / 521] x 100
Subtract the new number by the original number
681 - 521 = 160
160 ÷ 521 = 0.30710172744721687
0.30710172744721687 x 100 = 30.71%