26.1% is the change from 521 to 657
Calculation steps:
[( 657 - 521 ) ÷ 521] x 100 = 26.1%
Formula
Percentage change = [(657 - 521) / 521] x 100
Subtract the new number by the original number
657 - 521 = 136
136 ÷ 521 = 0.26103646833013433
0.26103646833013433 x 100 = 26.1%