3.65% is the change from 521 to 540
Calculation steps:
[( 540 - 521 ) ÷ 521] x 100 = 3.65%
Formula
Percentage change = [(540 - 521) / 521] x 100
Subtract the new number by the original number
540 - 521 = 19
19 ÷ 521 = 0.036468330134357005
0.036468330134357005 x 100 = 3.65%