6412.5% is the change from 8 to 521
Calculation steps:
[( 521 - 8 ) ÷ 8] x 100 = 6412.5%
Formula
Percentage change = [(521 - 8) / 8] x 100
Subtract the new number by the original number
521 - 8 = 513
513 ÷ 8 = 64.125
64.125 x 100 = 6412.5%
Example