83.69% is the change from 521 to 957
Calculation steps:
[( 957 - 521 ) ÷ 521] x 100 = 83.69%
Formula
Percentage change = [(957 - 521) / 521] x 100
Subtract the new number by the original number
957 - 521 = 436
436 ÷ 521 = 0.836852207293666
0.836852207293666 x 100 = 83.69%