86.56% is the change from 521 to 972
Calculation steps:
[( 972 - 521 ) ÷ 521] x 100 = 86.56%
Formula
Percentage change = [(972 - 521) / 521] x 100
Subtract the new number by the original number
972 - 521 = 451
451 ÷ 521 = 0.8656429942418427
0.8656429942418427 x 100 = 86.56%