27.64% is the change from 521 to 665
Calculation steps:
[( 665 - 521 ) ÷ 521] x 100 = 27.64%
Formula
Percentage change = [(665 - 521) / 521] x 100
Subtract the new number by the original number
665 - 521 = 144
144 ÷ 521 = 0.2763915547024952
0.2763915547024952 x 100 = 27.64%