-98.08% is the change from 521 to 10
Calculation steps:
[( 10 - 521 ) ÷ 521] x 100 = -98.08%
Formula
Percentage change = [(10 - 521) / 521] x 100
Subtract the new number by the original number
10 - 521 = -511
-511 ÷ 521 = -0.980806142034549
-0.980806142034549 x 100 = -98.08%