-57.58% is the change from 521 to 221
Calculation steps:
[( 221 - 521 ) ÷ 521] x 100 = -57.58%
Formula
Percentage change = [(221 - 521) / 521] x 100
Subtract the new number by the original number
221 - 521 = -300
-300 ÷ 521 = -0.5758157389635317
-0.5758157389635317 x 100 = -57.58%