-18.81% is the change from 521 to 423
Calculation steps:
[( 423 - 521 ) ÷ 521] x 100 = -18.81%
Formula
Percentage change = [(423 - 521) / 521] x 100
Subtract the new number by the original number
423 - 521 = -98
-98 ÷ 521 = -0.18809980806142035
-0.18809980806142035 x 100 = -18.81%